OLTP Performance Comparison: Solid-State Drives Vs. Hard Disk Drives 2
Total Page：16
File Type：pdf, Size：1020Kb
TEST REPORT JANUARY 2009 OLTP performance comparison: Solid-state drives vs. hard disk drives Executive summary KEY FINDINGS Intel Corporation (Intel) commissioned Principled Technologies (PT) to compare performance and power for online transaction Six internal SSDs delivered up to processing (OLTP) of two types of disk drives: 35 percent higher and better performance on our OLTP tests Intel X25-E Extreme SATA solid-state drives (SSDs) thanTEST a full REPORT24-disk enclosure of 15K standard 15K RPM SAS hard disk drives (HDDs) RPM SAS HDDs. FEBRUARY 2006 The SSD configuration, including We focused on a single usage scenario: that of a user needing the server, used nearly 35 percent additional server performance and wanting to know whether six less power when active and SSDs installed in server drive slots would provide better approximately 42 percent less performance and lower power consumption than a full external 24- power when idle than the HDD disk enclosure of HDDs. This is a user who does not need the configuration. additional storage capacity of the HDDs. The SSD configuration delivered higher performance without the We used the DVD Store Version 2 (DS2) test tool. DS2 is an open- need for an additional RAID source simulation of an online e-commerce DVD store. Its main controller or an additional external throughput metric is orders per minute, or OPM. We also measured drive enclosure. power consumption during the test and while the systems were idle. For the HDD tests, we tested a full shelf of 24 Seagate Savvio 15K SAS 73GB hard disk drives in a Newisys NDS-2240 enclosure attached to a server via an LSI Logic MegaRAID SAS 8888ELP RAID Controller. For the SSD tests, we tested six 32GB Intel X25-E Extreme SATA solid-state drives that we placed directly in the existing server drive slots, which connect to the built-in RAID controller. For both tests, we used a server with four six-core Intel Xeon X7460 processors at 2.66 GHz and 8 GB of RAM. We ran a single instance of DS2 and tested with a single 20GB database. In these OLTP tests, six internal SSDs delivered higher and better performance and lower power consumption than a full 24-disk enclosure of 15K RPM SAS HDDs. As a result, they are the better solution when a user needs additional drive performance but not the additional storage of the HDDs. DS2 results The internal SSD solution also saves Higher results are better the cost of additional RAID 80,000 64,973.66 controllers, external drive enclosures, 70,000 and rack space the HDDs require. 60,000 48,142.01 Figure 1 shows the OPM results for 50,000 the 24 HDDs and the six SSDs. 40,000 35% These results are the average OPM 30,000 higher performance during 200 seconds of OPMs 20,000 steady activity and heavy load during 10,000 a DS2 test run. We report the median 0 OPM result of three DS2 test runs. 24 Seagate Savvio 15K 6 Intel X25-E Extreme Six SSDs provided up to 35 percent SAS hard disk drives SATA solid-state drives better DS2 performance than a full enclosure of 24 HDDs: 64,973.7 OPM for the SSDs vs. 48,142.0 OPM for Figure 1: DS2 performance results in OPM for the two storage configurations. A the HDDs. higher OPM score is better. We used power analyzers to log the Active power consumption in watts power consumption (in watts) of the 900 Lower power consumption is better server and the enclosure (for the HDD tests) at one-second intervals during 800 776.9 the tests. Figure 2 shows the average 700 Enclosure power consumption during the same 600 plus HDD drives 501.4 periods and the same runs that 500 produced the results in Figure 1. 400 Watts Server 300 Server plus During a period of server activity, the 200 plus SAS SSD drives adapter SSD configuration, including the 100 server, used less power than the HDD 0 configuration: 501.4 watts for the SSD 24 Seagate Savvio 15K SAS 6 Intel X25-E Extreme SATA configuration vs. 776.9 watts for the hard disk drives solid-state drives HDD configuration. In fact, the Server plus SSD drives in the SSD configuration consumed only slightly Figure 2: Active power consumption in watts for the two storage configurations. more power, an additional 20.3 watts, Lower active power consumption is better. The SSD configuration, including the than only the Server plus SAS adapter server, used 35 percent less power when active. in the HDD configuration. We also used power analyzers to log Idle power consumption in watts the power consumption (in watts) of Lower power consumption is better 800 the server and the enclosure (for the 682.0 700 HDD tests) for two minutes while the server and drives were idle. Figure 3 600 Enclosure plus HDD presents those results. 500 drives 393.1 400 During an idle period, the SSD configuration, including the server, 300 Server Watts Server plus used less power than the HDD 200 plus SAS SSD drives configuration: 393.1 watts for the SSD adapter 100 configuration vs. 682.0 watts for the 0 HDD configuration. In fact, the SSD 24 Seagate Savvio 15K 6 Intel X25-E Extreme configuration used 10.9 fewer watts SAS hard disk drives SATA solid-state drives than the Server plus SAS adapter in the HDD configuration. Figure 3: Idle power in watts consumption for the two storage configurations. Lower idle power consumption is better. The SSD configuration, including the server, used 42 percent less power when idle. We also measured processor utilization during the peak testing time, the period of steady activity and maximum I/O. The three SSDs drove the processors approximately 52 percent more than the 24 HDDs; 39.1 percent for the SSDs and 25.7 percent for the HDDs. Workload We conducted our testing using DVD Store Version 2, an open-source application with a back-end database component, a front-end Web application layer, and a driver layer that operates as the middle tier and actually executes the workload. Because our goal was to isolate and test database server storage, we did not use the Web application layer. Instead, we ran the driver application directly via its command-line interface. Principled Technologies, Inc.: OLTP performance comparison: Solid-state drives vs. hard disk drives 2 DS2 models an online DVD store. Virtual customers log in; browse movies by actor, title, or category; and purchase movies. The workload also creates new customers. Browsing movies involves select operations, some of which use full-text search and some of which do not. The purchase, login, and new customer procedures involve updates and inserts, as well as selects. The workload’s main reporting metric is orders per minute, or OPM. For more details about the DS2 tool, see http://www.delltechcenter.com/page/DVD+Store. The server ran a single instance of DS2, which spawned 32 threads. This simulated a heavily loaded environment; the load-generating system ran with no think time, blasting requests as quickly as the server could handle them. The DS2 driver application creates an orders-per-minute performance counter on the system. We created a data collector set to collect statistics once every second. We ran the test three times and report results from the run that produced the median of the three OPM results. In addition, we monitored server performance statistics using the Reliability and Performance Monitor on the server. Our experiments showed that this function did not affect the performance of the test. We used these results to verify that neither the processor nor the memory was a bottleneck in the test. To record the server’s power consumption during testing, we used an Extech Instruments Power Analyzer/Datalogger. We used one Extech to measure the power draw of the server and a second Extech to measure the power draw of the drive array. We recorded power while servers were in idle and active states. Idle power is the average power consumption during two minutes while the server and drives were idle before DS2 runs. Active power is the average power consumption during 200 seconds of peak activity during the DS2 test run. We captured power consumption at one-second intervals. For the HDD results, we report the active and idle power consumption for both the storage array and server combined. We report active power consumption from the same runs that produced the median OPM values that we report. Test results Figure 4 provides test results for the two storage configurations. 6 Intel X25-E 24 Seagate Extreme SATA Savvio 15K SAS solid-state hard disk drives drives DS2 results for the three runs (higher is better) Run 1: OPM 64,973.7 48,172.0 Run 2: OPM 67,356.7 46,586.3 Run 3: OPM 64,203.0 48,142.0 Median OPM (higher is better) 64,973.7 48,142.0 Power measurements* from median run Idle power (lower is better) 393.1 682.0 Active power (lower is better) 501.4 776.9 Figure 4: Test results for the two storage configurations. *Note: The power measurement includes the power usage of the server and the enclosure (for the HDD configuration). Principled Technologies, Inc.: OLTP performance comparison: Solid-state drives vs. hard disk drives 3 Test methodology For the HDD tests, we installed the 24 HDDs into a Newisys NDS-2240 enclosure, which we connected to a server via an LSI Logic MegaRAID SAS 8888ELP RAID Controller. For the SSD tests, we placed the six SSDs in the existing server drive slots.