Applied Computer Cooling

By Spencer Ellsworth LAES 461/462

June 6, 2012

Abstract Cooling is a process integral to the operation of every computer in existence and many electronic circuits. The reasoning for this importance lies in the connection between component temperature and performance. This fact leads to the question in focus: To what extent does temperature affect computer performance? Research, experimentation, and analysis of collected data show that the computer does function better when cooling power is increased. These findings directly affect businesses that rely heavily on computers. Through the use of upgraded computer cooling systems, especially simple liquid cooling setups, companies may increase computer longevity and decrease maintenance and turnover costs. Contents

1 Introduction 1

2 Background 1 2.1 Important Places to Cool ...... 1 2.2 Casing and Airflow Theory ...... 2 2.3 Methods of Computer Cooling ...... 3 2.3.1 ...... 3 2.3.2 Liquid Cooling ...... 4 2.3.3 Miscellaneous Active Cooling ...... 4 2.3.4 ...... 5 2.3.5 Cooling Modificiations ...... 6 2.3.6 Electronic Cooling Settings ...... 7 2.4 Other Applications of Cooling ...... 7 2.4.1 Laptops ...... 7 2.4.2 Video Game Consoles ...... 7

3 Experiment 7 3.1 Tests ...... 7 3.1.1 Setup ...... 8 3.1.2 Description ...... 8 3.2 Computing and Business ...... 9 3.3 Test Conclusions ...... 11 3.3.1 Other Findings for Consideration ...... 11

4 Business Economics 12 4.1 Current Business Use of Cooling ...... 12 4.2 Connecting Conclusions and Business ...... 12 4.3 Summarizing the Project ...... 12 4.4 What Can Be Taken Away ...... 13

5 Related Work 13

6 Conclusion 13

7 Future Work 14 1 Introduction users. It would also be reasonable to as- sume that a computer owner who uses their In the ever-growing world of modern tech- machine for the purpose of making a living nology, one of the most integral pieces of stands to lose much more from a malfunc- equipment is the . Per- tion than does an owner whose livelihood is sonal computers have come a long way from not tied up in their computer. the very first electro-mechanical binary pro- Before examining the data surrounding grammable computer in 1936 and the first impact costs and related issues, it is im- personal computer in 1953 [2]. Computers portant to discuss the theory and methods have changed the ways in which people do of cooling computers in order to provide a work, learn, access information, live, and proper background for the experiment de- interact. However, even such machines of tailed in this paper. This will be followed great power and ability lack perfection. by a description of the experiment and the Computers put off heat. As mechanical results collected from the tests. Finally, and electrical objects, this is to be expected. the connections between these tests and the However, every mechanical and electrical de- business enviroment will be drawn and fu- vice has a point at which the temperature in ture developments for this projects listed. and around it begins to cause issues. Even prior to this point, performance may be af- fected by increased amounts of heat [3]. This 2 Background is the key focus of this work: the affect of temperature on computer performance. In the following subsections, descriptions “Computer cooling is vital for proper will be given for the practical applications of function and longevity of electronic compo- cooling computers. It is important to note nents” [25]. The practical application of that not all of these locations need a cool- cooling will be discussed in section two, in- ing solution above what is typically provided cluding specifics for where and how cooling with the stock parts. However, for many of should be applied. However, the implica- these locations, improved cooling does lead tions of this “proper function and longevity” to improved performance. go beyond simple home computer usage. In 2002, a study found that, of the 2.1 Important Places to Cool more than one billion personal computers sold since the 1970s, seventy-five percent of A glance at the website of any retailer of these were for work and professional use [10]. computer cooling equipment makes it obvi- While this number has risen since its discov- ous that the greatest number of cooling so- ery thanks to the growing number of busi- lutions available on the market are aimed nesses, these 2002-numbers are sufficient to toward use on the prove the point here: any problems that may [29]. Also known as the CPU, this compo- resolve in a computer, in regards to function nent is the brain of the computer. Any prob- or longevity, would have a greater impact lems with the CPU bring assurances of com- upon professional users as compared to home puter malfunction. A faulty CPU cooler, or

1 the lack of a CPU cooler, can cause instanta- neous CPU overheating and immediate com- puter shutdown [4].

While the cooling solutions need not be as intense and powerful as those for the CPU, it is nonetheless very important to cool the . The GPU may take the form of an integrated graph- ics unit on the or a separate graphics card. Often, the separate graphics Figure 1. Diagram of motherboard cards contain their own cooling mechanisms, locations [5, 4]. integrated with the card and not able to be modified. 2.2 Casing and Airflow Theory An important distinction lies between the The north and south bridges handle all two genres of cooling solutions: active and communications on the motherboard. This passive. The difference between them is in- includes communication between integrated tegral to the understanding of theories of components and motherboard peripheral [9]. cooling. Active cooling solutions are com- Some type of cooling setup is almost always ponents such as fans or waterblocks, typi- utilized for these two areas. Upgraded cool- cally containing moving parts [4]. On the ing solutions may be used, but they are not other hand, passive cooling involves non- commonly available [29]. mechanical methods of cooling, such as heat sinks, heat pipes, or even leaving the com- ponents open to the air [4]. These examples The unit of the computer will be discussed in greater detail in section generates a lot of heat during the transfer of 2.3. electricity. All power supply units contain When looking to improve the cooling of their own solutions for cooling the internal a computer, it is important to take into components. These are not typically modi- consideration the component storage. Com- fied for greater cooling, as they are primarily puter cases have been built from a large va- self-contained units. riety of materials, and each material has its own . Acrylic, steel, Hard disk drives and RAM (Random Ac- and aluminum cases are popular options. cess Memory) are oftentimes left uncooled. Acrylic, while attractive, tends to have a However, even cooling these components will much lower conductivity than steel, which provide some measure of improved perfor- has a lower conductivity than aluminum. mance. Aftermarket parts are available for The lower the conductivity, the more heat purchase that provide cooling solutions for will be contained passively by the case [25]. these areas [29]. This excess heat will need to be moved away

2 from internal components, which can be ac- The amount of air being drawn into the complished in large part by active cooling case and ejected from it affects the ambient solutions. case temperature. When more air is being There are considerations to be made drawn into the case than ejected, a positive within the case as well. Airflow can signif- pressure system is created [25]. The advan- icantly affect the cooling of a computer if tages of positive pressure in the computer heat is not properly dispersed from around case have nothing to do with cooling, and the components. The following diagram this system will decrease the cooling effec- shows the theoretical flow of air through tiveness of any cooling solutions being used. a standard-size , which is However, a case with negative pressure will equipped with air cooling solutions, taking more effectively cool the contained compo- into account scientific properties of heat (in nents, as this system maintains a constant this case, ) [14]. flow of air through the case [25].

2.3 Methods of Computer Cooling While certainly the most common of all methods of computer cooling, fans are only the tip of the iceberg when it comes to solu- tions for lowering component temperature. In the following sections, a brief overview will be given to showcase some of the myr- iad options. Air cooling is by far the most common and, thus, the foremost discussed.

2.3.1 Air Cooling

Choices for computer fans cover a vast range, Figure 2. Diagram of theoretical computer as a number of variables combine to create airflow [6]. the options. Fans may vary by size, speed (and whether or not they are variable speed), As can be seen above, ambient tempera- decibel level, and the number of fins [25]. ture air enters the front of the case and be- Additionally, the airflow of the fan may be gins passing over the components. Some of different depending on how it is designed. this air is used to cool the central processing Axial-flow fans are by far the most common at the rotational arrow. The now heated air and can by likened to a ceiling fan. Centrifu- is often carried out the back or top of the gal fans use impellers to draw air into them- case by means of a fan. Some air is addi- selves and force it in another direction [23]. tionally drawn up through the power supply Cross-flow fans also work with impellers to unit at the rear back of the case and ejected move air without the direction change [7]. from the back. The reasoning behind the variables in

3 computer fans often remains situational. mentioned previously as important places, The size of a fan is often determined by its can be cooled with a single liquid system placement in the computer case or with the setup. However, these setups typically re- component. Higher fan speeds are typically quire larger amounts of space in which to fit desired in server setups, computers for gam- the , tubes, cooling mounts ing, or computers that are used for heavy (the mechanisms by which components are graphics processing. Utilizing fans with vari- directly cooled), and sometimes a coolant re- able speeds may save energy, allowing the sevoir or separate power supply [24]. They user to employ higher speeds during times also require a certain high level of technical of heavier usage. The speed of the fan also knowledge to acquire the necessary compo- has an impact on the decibel level of the nents and assemble them properly [12]. fan’s ambient noise. This may be an ad- For those whose liquid cooling needs are ditional reason for utilizing variable speed less intensive or those whose technical ex- fans. Consequently, some users desire qui- pertise is not at the level of assembling a eter computer setups and are willing to sacri- custom liquid system, simpler liquid cool- fice money and/or performance to gain lower ing setups exist. These systems are closed noise levels [4]. loops comprised of a cooling mount, several tubes, and the radiator apparatus. While 2.3.2 Liquid Cooling they typically only cool the central process- ing unit, these liquid cooling kits are more In recent years, there has been a growth cost-effective than purchasing separate com- in another area of computer cooling: the ponents [26]. The skills necessary to install use of liquid to lower component one of these closed-loop systems are also temperatures. Liquid cooling systems work much less technical than those with a cus- much like the cooling systems in automobiles tom setup [4]. as coolant is passed over vital components, draws away heat, has this heat dispersed by 2.3.3 Miscellaneous Active Cooling means of a radiator, and continues through the cooling circuit again. When liquid cool- Air and liquid solutions are not the only ing systems were relatively new technology, methods of active cooling. However, they it was necessary to assemble all of the com- are the most common on account of other ponents individually, fit them into the ma- methods being more expensive, less feasible, chine, and tune everything manually [12]. or aimed at more specialized setups and sit- However, as liquid cooling increases in pop- uations. In the fairness of presenting a broad ularity, other options have arisen that make overview of computer cooling, some of these this cooling solution more viable for those other methods are worth mentioning. who are less technically inclined. Full-immersion cooling setups involve Custom liquid cooling setups remain submerging all of the computer components the best friend of those looking to lower (except the harddrive) into non-conductive their component temperatures by a great coolant and then allowing the ambient air degree. Nearly all of the components, or a radiator carry away the heat generated

4 from the components. This setup is essen- 2.3.4 Passive Cooling tially liquid cooling for the entire computer. While it may look impressive, as it is of- A number of passive cooling solutions exist ten built in an aquarium tank with colored that are to be used in conjunction with var- lights, it is also an expensive solution, as the ious active cooling systems. Even in stock most popular liquid coolant to use is min- computers, some of these solutions may be eral oil, which is difficult to acquire in many seen in conjuction with fans or liquid setups areas [18]. [4]. In fact, even when attempting to achieve benchmark scores through the more extreme methods of active cooling, various passive The use of dry ice, , and cooling solutions are still integrated into the liquid helium in computer cooling falls in the setup as a whole [1]. realm of “extreme cooling.” Because of the Heatsinks are designed to transfer heat short lifespan of such materials as coolants, into themselves from components and dis- they are typically only used for short over- sapate it into the surrounding air. They clocking sessions. is the pro- are typically designed with a large surface cess of pushing computer components to area-to-volume ratio, using materials that their limits in order to benchmark the ex- are high in thermal conductivity. Heatsinks tent to which these components can perform. must also have perfect contact with the com- Each of these three coolants tends to pro- ponent for the best [20]. This vide incredibly low temperatures with liq- point in particular will be discussed in sec- uid nitrogen performing better than dry ice tion 2.3.5. and liquid helium lowering temperatures fur- Heat pipes are typically used in conjunc- ther than the other two. As previously men- tion with heatsinks, where the heat pipes tioned, their short lifespan makes them of lit- syphon heat off a component and transfer it tle use for anything other than benchmark- to a another heatsink. They are designed ing. Additionally, the cost factor and diffi- as thin pipes with water running through culty of implementation would make regular the hollow center. Using laws of heat trans- use incredibly inefficient [1]. fer, heat pipes raise the thermal conduc- tivity of the cooling system many times Phase change cooling involves the use of more than it would be otherwise. How- basic principles to cool com- ever, heat production does not take place in puter components, especially the central heat pipes. Therefore, achieving tempera- processing unit. Using either evaporators tures lower than the ambient level is impos- or special liquid-chilling units, the tempera- sible via alone [19]. On the other ture of the coolant is dropped below freezing hand, producing heat and consuming energy to provide an even greater boost to compo- is part of another method of passive cooling, nent cooling. Aside from cost, the primary known as Peltier, or thermoelectric, cooling. trouble with phase change systems is that Peltier cooling utilizes the Peltier effect they are quite noisy on account of the spe- to cool components, hence the name. The cial components used [1]. Peltier effect involves using a voltage and

5 thermocouples (dissimilar metals connected these companies is to further improve upon in such a way that there is a temperature their own products beyond their stock im- differtial between them) to create a sort of plementations. heat pump. When several of these setups are put in series, they form the basis for a ther- Thermal compound, also know as ther- moelectric, or Peltier, cooling mechanism. mal paste, thermal grease, or, more techni- As the usage of voltage technically causes cally, “Thermal Interface Material,” serves Peltier setups to become active cooling so- to improve the movement of heat from the lutions, the base components are passive de- central processing unit or other computer vices. Peltier coolers have no moving parts, component to the heatsink or other cooling require low maintenance, and having cooling interface. The reason for using thermal com- capabilities that are on par with larger and pound is that the surfaces of cooling inter- more complicated active solutions, such as faces and computer components are not per- phase change cooling. Despite these advan- fectly flat and even. A small application of tages, they are very complicated to set up thermal grease between these surfaces serves and properly tune to the computer [21]. to fill the miniscule air pockets and form a Heat spreaders serve to do just as their more conductive contact between those same name suggests: spread the heat from a com- surfaces [22]. ponent over a larger surface area. This im- As previously mentioned, heatsinks must proves the dissapation of said heat. Typ- have perfect contact with the component for ically found on modules of RAM (random the best heat transfer. While thermal com- access memory), heat spreaders are a cost- pound helps to “fill in the gaps, another op- effective solution to increased RAM cooling tion is often utilized, especially by computer [11]. cooling enthusiasts. Known as heatsink lap- “Open bench” computers are designed to ping, the process essentially involves utiliz- leave all of the components open to the sur- ing sandpaper of multiple grits to flatten and rounding air. Instead of residing in a com- polish the contact surface of the heatsink to puter case, the components are mounted on a more perfect degree. Often, this process a skeletal rack so that they are all visible provides a decent drop in component tem- and to allow air to more freely pass through peratures at a relatively low cost [15]. them. Various active cooling solutions are used in conjuction with this setup. [4]. The idiom of “cleanliness is next to godli- ness” applies to computing as well. However, 2.3.5 Cooling Modificiations properly managing all of the cabling within the computer case will provide benefits be- Various cooling solutions for computer com- yond merely looking nice. Cable manage- ponents may be further modified in order ment will improve the airflow within the case to increase their efficiency. While these are and keep components cooler. In addition to not strictly neccessary, many of them have properly managing cables, using rounded ca- been implemented by companies in the com- bles instead of flat or ribbon-style cables will puter cooling industry. The intention of prove beneficial [4].

6 2.3.6 Electronic Cooling Settings laptop components are intentionally brought into contact with the laptop casing in order Lower computer component temperatures to dissapate heat passively [4]. may also be acquired without the use of physical setups. The process of “soft cool- ing,” as these methods are often termed, 2.4.2 Video Game Consoles varies based on the components. Some com- Video game console cooling solutions are ponents may be undervolted. The process sought by hardcore gaming enthusiasts. Be- of undervolting involves lowering the volt- cause modern video game consoles are es- age provided to the component [8]. While sentially computers inside, many of the this may decrease performance, less voltage same cooling solutions for computers can be in the component will result in less heat be- adapted to video game consoles. Heatsink ing emnated [4]. is another modifications, air cooling upgrades, and liq- form of soft cooling. This lowers the cen- uid cooling setups are sold for such consoles tral processing unit’s speed [8]. The reduced as the Microsoft Xbox, Nintendo Wii, and workload may result in some decreased per- Sony PS3 [27, 28]. formance, but it will also cause the CPU run at a lower temperature [4]. Occasionally, “control of halt” instructions can be utilized 3 Experiment to stop or pause unnecessary computer com- ponents, reducing heat through reduced ac- “What impact does computer cooling have tivity [8]. on businesses, and what affect might this have on maintenance and turnover costs?” This project intended to investigate the 2.4 Other Applications of Cooling effect of temperature on computer perfor- The cooling of electronic components ex- mance. Having covered a broad overview tends beyond the use in desktop comput- of the integral components to be cooled and ers. Laptop computers are another obvi- the methods by which this could be accom- ous application. Additionally, the rise of plished, this information was then put into video game consoles has lead to a new niche practice. The intention was to collect solid in component cooling as people strive for data regarding the effectiveness, and impor- the best performance possible in their video tance, of various computer cooling solutions. games. To narrow the field of investigation and to make it more relevant to real world issues, 2.4.1 Laptops the question above was the focus of the ex- periment. There are far fewer options for the cooling of laptop computers than for desktop com- 3.1 Tests puters because of the smaller enclosure of the components. Typically, laptops utilize In order to more closely adhere to the pa- combinations of heatsinks, heat pipes, and rameters of the question under investigation, air cooling to disperse heat. However, some all of the variables were chosen to be as

7 closely representative of a real work environ- cooling solutions. Heatsinks, heat spreaders, ment as possible, while allowing for certain and the arrangement of components and ca- limitations of resources and requirements for bles within the case were not changed from control. between tests. The following are the three test cases. 3.1.1 Setup 1. Stock Air-Cooled System The experiment was performed in an en- 2. Modified Air-Cooled System closed, 10’ by 12’ room. The size room was 3. Basic Liquid-Cooled System representative of many office workspaces, and the reason for enclosure lies in the lack The stock air-cooled system utilizes no of proper air circulation in some professional additional cooling solutions other than those environments. A consistent temperature of that were already built-in to the computer 76 °F was maintained in the room so that components. Therefore, the components in any environmental change came from the this setup are all passively cooled with the computers themselves. Aside from the pri- exception of the CPU, as the heatsink has mary computer on which tests were being an integrated cooling fan. run, there were four other running comput- In the modified air-cooled system, the ers in this room: three desktops and a lap- air-cooling was upgraded to improve the top [4]. Again, the purpose in adding these cooling efficiency. Two Masscool 120mm extra computers was to simulate a realistic fans were added to the case. One was placed work environment. in the front of the computer case in order to The fifth computer in the room was the draw in more air. The second was affixed in computer on which the cooling tests were to the upper rear of the case to exhaust warm be performed. This computer was a custom- air. built machine in a DiabloTek CPA-0280 The third setup changes directions away Elite ATX Mid Tower Case. The mother- from air cooling. Both of the case fans were board was a GIGABYTE GA-880GM-USB3 removed. The CPU heatsink with its inte- REV3.1 AMD 8 Series AM3+ with an AMD grated fan was exchanged for a Corsair CW- Phenom II X6 1035T processor and 4GB of 9060001-WW Hydro H40 CPU liquid cooler. DDR3-1333MHz RAM. The hard drive was Each setup was chosen for specific rea- a Seagate Barracuda 7200 RPM 500GB hard sons. The stock setup carries the same disk drive. amount of cooling that many business-class computers have as standard. Upgrading the 3.1.2 Description air cooling is an inexpensive modification performed on many computers. The liquid For the purpose of maintaining a control cooler takes the cooling to the next level. setup and investigate multiple solutions, This Corsair H40 was chosen for a number three different variations on the same hard- of reasons, all of which would prove benefi- ware were used. From one test to another, cial to a business. It is easy to install; fully- the only things that varied were the active enclosed, requiring no maintenance; and cost

8 effective. It promises a level of performance – Setup 2: 40 °C that is sufficient for many business-class ap- – Setup 3: 25 °C plications and hardware setups [4].

3.2 Computing and Business Four different software programs were used in testing the setups: OCCT, PassMark Per- formanceTest x64, SuperPi + CoreTemp, and PassMark BurnInTest Pro x64. All four utilized different methods of stress- testing the computer, pushing the compo- nents to their limits, thereby generating the most heat possible. The heat and corre- sponding performance of the computer were The PassMark PerformanceTest x64 the items under investigation through this runs a suite of tests agains the CPU, graph- project. For the following data charts, Setup ics card, hard drive, RAM, and optical drive. 1 refers to the stock air-cooled setup, Setup The program gives a result as a number rat- 2 is the modified air-cooled setup, and the ing, which is a compilation of the scores. liquid-cooled setup is labelled as Setup 3. Typically, higher numbers are better. The “Idle CPU” refers to the temperature of the results from PerformanceTest are not as high CPU before the test was run, and “Load overall for these three setups as they could CPU” is the maximum temperature reached be, thanks to the lack of a separate graph- by the CPU over the course of the test. ics card (the graphics processing unit in this In OCCT, the Automatic Test was run setup is integrated into the motherboard). for one hour, configured to use a large data set. This test pushes the CPU to its full ˆ Rating capacity for one hour while running various calculations and processes. Temperatures – Setup 1: 883.5 are measured utilizing a thermometer built – Setup 2: 885.3 into the motherboard. The results were as – Setup 3: 893.9 follows:

ˆ Idle CPU

– Setup 1: 21 °C – Setup 2: 21 °C – Setup 3: 10 °C

ˆ Load CPU

– Setup 1: 41.5 °C

9 The third test that was run utilized two PassMark BurnInTest Pro x64 is de- different programs. SuperPi is a program signed to push computer components to a that calculates the number pi to a specified certain degree in order to get them past the number of digits. The highest number of “burn-in” time period. This period is during decimals that could be calculated was thirty- which any components suffering from manu- two million. During the process of running facturer defects or other damages are bound SuperPi, the program, CoreTemp, was used to fail [17]. Essentially exercising the com- to track the change in temperature of the ponents, BurnInTest Pro stresses the “CPU, CPU throughout the SuperPi run. SuperPi hard drives, RAM, CD-ROMs, CD burn- also reports the length of time it took to cal- ers, DVDs, sound cards, 2D graphics, 3D culate the specified number of decimals. For graphic, network connection, printers, video all three setups, the length of time used was playback” [16]. During the execution of the approximately twenty-three minutes. There tests, the highest temperatures were tracked. was very little variation in time. The results were as follows:

ˆ Idle CPU ˆ Idle CPU – Setup 1: 22 °C – Setup 2: 19 °C – Setup 1: 23 °C – Setup 3: 13 °C – Setup 2: 19 °C ˆ Load CPU – Setup 3: 12 °C – Setup 1: 32 °C ° – Setup 2: 26 C ˆ Load CPU – Setup 3: 20 °C

ˆ Time – Setup 1: 32 °C

– Setup 1: 23 minutes, 12 seconds – Setup 2: 29 °C – Setup 2: 23 minutes, 11 seconds – Setup 3: 20 °C – Setup 3: 23 minutes, 11 seconds

10 3.3 Test Conclusions feet from the user. Any noise coming from the power supply unit was quiet enough as to Following the tests, conclusions were drawn be nearly negligible. During the tests involv- from the collected data. Typically, while ing the liquid setup, the noise level was lower the CPU was idle, having an upgraded air- than that during the stock air-cooled system cooled system did not improve the CPU’s tests. While the liquid cooling mechanism temperature to a large degree. The differ- does include a fan in the radiator setup, the ence in temperatures for an idle CPU was relative noise of this fan was quieter than much more noticeable when comparing the that of the heatsink and fan combination stock air-cooled system and the upgraded CPU cooler. air-cooled system to the liquid-cooled sys- tem. Idle CPU temperatures with the liquid- cooled system were always close to half of the idle CPU temperatures for the stock air- cooled system. When the CPU is under load, the ad- Another finding of the testing was re- vantages of a better cooling setup shines lated to the relative temperature of the test- through in the data. In a majority of the ing environment. Because all heat from the tests, the upgraded air-cooled system per- computer was eventually exhausted from the formed moderately better than the stock air- computer case, whether passively (stock air- cooled system. However, the liquid-cooled cooled system) or actively (upgraded air- system performed over three times as well cooled system and the radiator of the liquid- as the stock air-cooled system in a majority cooled system), the temperature of the test- of the tests. ing environment varied from one setup to the next. Subjectively, it seemed that the 3.3.1 Other Findings for Considera- temperature of the testing environment was tion cooler during the liquid-cooled system tests Throughout the process of testing, several than during the stock air-cooled system other discoveries were made. Each of the tests. The environmental temperature dur- three setups varied in the level of sound they ing those stock air-cooled tests was several produced. Between the upgraded and stock degrees warmer than the initially measured air-cooled systems, the addition of more fans room temperature of 76 °F. However, during increased the ambient noise level around the the liquid-cooled system trial, the temper- computer by a great degree. While no data ature varied little from the initial reading. was collected in regard to decibel levels, the Additionally, the environment also seemed difference was noticeable. In the stock air- cooler during the stock air-cooled system cooled system, the fan integrated into the tests than while the upgraded air-cooled sys- CPU heatsink was the only noise source. tem tests were being performed. The addi- When the computer case was closed, the tion of more fans to the cooling system lead noise level was not very noticeable with the to the exhaustion of greater amounts of com- computer case at a distance of one and a half ponent heat into the testing environment.

11 4 Business Economics by the computer in order to a liquid-cooled system instead of a stock air-cooled system. The importance of these findings applies to It should be pointed out that this extra elec- businesses and individuals alike. However, tricity is nearly negligible, considering that most of the aforementioned do not investi- the power supply unit of the computer draws gate into improved computer cooling, much a certain amount of electricity regardless of less know of the possibilities for their ma- the use [4]. chines. This is what they should know. The environmental cost plays a role in this comparison. The use of less electricity 4.1 Current Business Use of Cool- is friendlier to the environment. This fact ing cannot be disputed. It would follow that, if all of the components (computer cooling sys- Computer cooling plays an important roll tem and ) draw less electric- in many businesses today. Without proper ity, as they would if a liquid-cooled system cooling, high-powered machines and appli- was in use, the liquid-cooled computer setup cations would not run to their full potential, has a lower environmental cost than a stock nor would they last as long without mainte- air-cooled computer setup. nance. “Too much” cooling is an impossibil- ity, and no harmful effects will come from the While not applicable to all businesses, utilization of large amounts of cooling com- productivity cost from noise level may play a ponents, even to extreme degrees. It may roll for some users. As previously reported, be argued that any business that invests in the relative noise level was noticeably dimin- advanced cooling systems for their comput- ished through the use of the liquid-cooled ers will not see detrimental performance on system, as compared to the stock air-cooled account of the change in setup. setup.

4.2 Connecting Conclusions and 4.3 Summarizing the Project Business The topic of computer cooling is an unseen Empirical data regarding the cost of electric- and confusing component of computer sys- ity for air conditioning varies widely within tems for many people. Few people fully un- individual cities. Thus, a direct compari- derstand the combination of physics, chem- son of the cost of the air conditioning por- istry, and engineering behind computer cool- tion of an electricity bill (from a business) ing setups. However, the advantages of ad- to the cost of computer cooling upgrades vanced computer cooling can be acquired within that same business would be inaccu- even by those without a mastery of the topic! rate and partial speculation. However, the In summary, this goal of this project was general logic of such a comparison should be to make the concepts behing the cooling of sufficient illuminate the point. The compar- computers more accessible to those who do ison would have to be between the electricity not necessarily need or want an engineer- used to cool the area occupied by the com- level comprehension of the background prin- puter and the extra electricity drawn upon ciples. The research portion aimed to give a

12 broad overview of the myriad of topics and ponent against others of its kind in order to methods for applied computer cooling. Ex- determine the “top” setup, usually in terms periments were performed to collect some of performance [4]. However, comparisons empirical data. This data compared three between these “top component” tests and different computer cooling setups mainly on the results of this project would produce no the grounds of performance. The results relevant data for several reasons. First, com- of the experiments were then connected to ponent comparison tests always look at dif- their meaning for business users. Based on ferences among a group of like components these connections, the ultimate conclusion (i.e. all fans, all liquid coolers, all heatsinks, for businesses with computers was drawn etc.). The other reason is that component (and it will be shared!) performance tests often do not place as much emphasis on cost-effectiveness as this project 4.4 What Can Be Taken Away has [4]. Considering the business implications of The advantages of advanced computer cool- computer cooling choices rarely occurs. Of- ing can be acquired with a lot of invest- ten, the comparison studies are geared to- ment. For many computer users, even those ward computer enthusiasts and avid com- with high power machines, an enclosed liq- puter gamers whose livelihood is not so in- uid cooling system will be sufficient. The timately connected with their systems. Ad- setup used in this experiment, the Corsair ditionally, very few measurements have been CW-9060001-WW Hydro H40 CPU liquid performed to include components of various cooler, retails for approximately $50 USD, genres, whether working in tandem or one- a price that appears to be well worth the versus-another [4]. benefits provided. Additionally, while this project focused most of its work on business computer users, many of the same conclu- sions can be applied to personal computer 6 Conclusion use. To conclude this project, a disclaimer must 5 Related Work first be made regarding this work. None of the experiments were performed under pris- It should be noted that this project is not tine conditions. The accuracy of the empiri- the first work of its kind. Many technol- cal data that was collected may have been ogy websites create comparison tests of com- compromised in any number of ways, es- puter cooling components, typically grouped pecially including changes in environmental by type of component (heatsink, liquid CPU conditions from one test to the next. How- cooler, fan, etc). Xoxide, Tom’s Hardware, ever, the validity of the conclusion remains: FrostyTech, TechSpot, and Benchmark Re- liquid-cooled computer systems perform bet- views are among the most prominent groups ter than their air-cooled counterparts, and involved in component analysis.The inten- the use of liquid-cooled computer systems tions of such tests are often to pit one com- would be advantageous for businesses.

13 7 Future Work The second area in which this project might broaden its horizons is practical test- This project is only the tip of a large ice- ing in a true business environment. Being berg of computer cooling methodology and able to perform a long-term test of the im- systems. From this work, two distinct lines plementation feasibility, financial advantage, of expansion have been wrought, each taking an improvements to computer performance certain approaches to greater extents. and longevity in a professional environment First is the expansion on the background would lend great weight to the validity of the and overview of computer cooling. The topic conclusions of this paper. Additionally, es- of methodology and process is far more vast tablishing these comparisons within compa- than that which is covered in the beginning nies of various industries would provide the sections of this paper. At this time, no grounds for analyzing the extent to which guidebook to computer cooling exists, but different cooling systems are advantageous the potential for such a manual exists here. for varying levels of computer usage.

“Now this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning.” -Sir Winston Churchill, 1942

Licensed under: Creative Commons, June of 2012.

14 References

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Article giving an overview of extreme cooling.

[2] Computer Hope, “When was the first computer invented?” http://www. computerhope.com/issues/ch000984.htm, 2012.

Article discussing early computers.

[3] Duffy, “Current and Resistance,” http://physics.bu.edu/∼duffy/PY106/Resistance. html, July 1999.

Webpage describing the effect of temperature on current.

[4] S. Ellsworth, “Senior Project Findings,” 2012.

Various findings from the experimental portion of my senior project.

[5] Entaonline, “Gigabyte GA-880GM-USB3 Motherboard Phenom II Socket AM3 AMD 880G RAID Gigabit Ethernet (rev 3.1),” www.entaonline.com/ product/Gigabyte-GA880GMUSB3-Motherboard-Phenom-II-Socket-AM3-AMD GA-880GM-USB3.htm, 2012.

Webpage containing a motherboard photograph to edit.

[6] Fosnez, “File:computer case coolingair flow.png,” http://en.wikipedia.org/wiki/File: Computer case coolingair flow.png, December 2007.

Diagram showing theoretical computer airflow through a standard ATX computer case.

[7] Hengcheng Co.,Ltd., “What Is Cross Flow Fan,” http://www. crossflow-fan.com/about-cross-flow-fans.htm.

Article discussing the nature of cross-flow fans.

[8] Janalta Interactive Inc., “What is Softcooling?” http://www.techopedia.com/ definition/24919/softcooling, March 2012.

Webpage definining softcooling.

[9] G. Jones, “ & Core-Logic : The Deep Stuff,” http://www. informit.com/articles/article.aspx?p=339936, October 2004.

15 Article discussing the purpose of north and south bridges on a motherboard.

[10] M. Kanellos, “PCs: More than 1 billion served,” http://news.cnet.com/ 2100-1040-940713.html, June 2002.

Article discussing the prominence of PCs in the business and home sectors.

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Article discussing the usefulness of heat spreaders.

[12] M. Kyrnin, “What is Liquid Cooling?” http://compreviews.about.com/od/cpus/a/ LiquidCooling.htm.

Guide discussing what liquid cooling is.

[13] S. Mueller, Upgrading and Repairing PCs. Que Publishing, 2005.

Book on upgrading and repairing PCs.

[14] C. Nave, “Heat transfer,” http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/ heatra.html, 2012.

Webpage describing the scientific properties of heat transfer.

[15] Overclockers Club, “How to Lap a Heatsink Guide,” http://www.overclockersclub. com/guides/lapping/, November 2002.

A guide to the process of heatsink lapping.

[16] PassMark, “Passmark burnintest software,” 2012), howpublished = ”http://www. passmark.com/products/bit.htm”, annote = ”Webpage describing PassMark Burn- InTest.”.

[17] Puget Systems, “Burn-In Process,” http://www.pugetsystems.com/included.php? inc=burnin, 2012.

Webpage describing the process of burning-in components.

[18] ——, “Mineral Oil Submerged Computer; Our Most Popular Custom PC,” http:// www.pugetsystems.com/submerged.php, 2012.

Webpage describing a full-immersion computer setup.

[19] Steinbrecher, Tillmann, “THE HEATSINK GUIDE: Heat pipe information,” http: //www.heatsink-guide.com/content.php?content=heatpipes.shtml, 2010.

16 A guide to heat pipes.

[20] ——, “THE HEATSINK GUIDE: Information about heatsinks,” http://www. heatsink-guide.com/content.php?content=heatsinkinfo.shtml, 2010.

A guide to heatsinks.

[21] ——, “THE HEATSINK GUIDE: Peltier Guide,” http://www.heatsink-guide.com/ content.php?content=peltierinfo.shtml, 2010.

A guide to Peltier cooling.

[22] G. Torres, D. Barros, and C. Lima, “How To Correctly Apply Thermal Grease,” http: //www.hardwaresecrets.com/article/How-To-Correctly-Apply-Thermal-Grease/274/ 1, January 2006.

A guide to Thermal Interface Material.

[23] United Nations Environment Programme, “Electrical Energy Equipment: Fans and Blowers,” www.retscreen.net, 2006.

Document describing types of fans.

[24] T. Wilson, “HowStuffWorks ”How Liquid-cooled PCs Work”,” http://computer. howstuffworks.com/liquid-cooled-pc.htm.

Article describing how liquid cooling works and the components of such a system.

[25] Xoxide, “Computer Cooling Guide,” http://www.xoxide.com/computer-cooling.html, 2005.

Article describing the basics of computer cooling practice and theory.

[26] ——, “Computer Kits at Xoxide.com - Liquid Cooling Systems,” http: //www.xoxide.com/watcoolkit.html, March 2012.

The homepage of the Xoxide company. Specific focus on the top navigation bar.

[27] ——, “Wii & PS3 Console Mods,” http://www.xoxide.com/console-mods.html, March 2012.

Webpage of Wii and PS3 console mods.

[28] ——, “Xbox 360 Mods and Cooling,” http://www.xoxide.com/xbox-360-mods.html, March 2012.

17 Webpage of Xbox 360 console mods.

[29] ——, “Xoxide.com,” http://www.xoxide.com/, March 2012.

The homepage of the Xoxide company. Specific focus on the top navigation bar.

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