CompTIA A+ Exam Memory Notes

Sky D. Semone September 2018

1 Questions

All questions taken from 2016 reference guides and online questions. [2] [1]

1. Random Access Memory (RAM) falls into the category of the so-called volatile storage media. It requires a continuous flow of electricity to pre- serve its contents thus all the data stored in RAM lasts only while the power is on. • True 2. Which of the answers listed below refer(s) to the characteristic feature(s) of Static Random Access Memory (SRAM)? • Faster than Dynamic Random Access Memory (DRAM) • Volatile storage media type • Utilized for CPU memory chips 3. Which of the following answers describes(s) the characteristics of Dynamic Random Access Memory (DRAM)? • Volatile storage media type • Slower than Static Random Access Memory (SRAM) • Widely used as system’s primary storage media (regular RAM mod- ules installed in memory slots on the ) • Less expensive in comparison to Static Random Access Memory (SRAM) 4. The term ”Synchronous Dynamic Random Access Memory (SDRAM)” refers to a broad category of DRAM modules that rely on the signal sent by the system clock in order to coordinate their functioning with other internal PC components. • True 5. Which of the statements listed below are true? • The speed of the system is measured in clock cycles

1 • In computer architecture, the term ”word” refers to a group of bits processed as a unit • A single clock cycle is an equivalent of a period of time between two adjacent signals sent by the system clock • The speed of the system bus in modern PCs is measured in MHz (i.e. millions of cycles per second) • Depending on the system specs, a single clock cycle might be an equivalent of multiple ticks of the system clock 6. A Single Data Rate Synchronous Dynamic Random Access Memory (SDR SDRAM) can read/write one word of data per clock cycle. • True 7. What is the number of contact pins used in SDR SDRAM modules? • 168 8. The placement of a notch on the RAM module contact surface allows for proper alignment of the module with the memory bank on the mother- board and prevents the installation of incompatible memory types. • True 9. What are the characteristic features of the Synchronous Dynamic Random Access Memory (DDR SDRAM) • 184 contact pins • Reads/writes 2 words of data per clock cycle • 1 notch on the module contact surface 10. Which of the answers listed below refers to the industry name used for DDR-333 modules? • PC-2700 11. What is the peak transfer rate of a DDR-266 module? • 2133 MB/s 12. What are the characteristic features of the Double Data Rate 2 Syn- chronous Dynamic Random Access Memory (DDR2 SDRAM)? • Reads/writes 4 words of data per clock cycle • 1 notch on the module contact surface • 240 contact pins 13. Which of the following answers refers to the industry name used for DDR2- 1066 modules?

2 • PC2-8500 14. What is the total bandwidth of a DDR2-533 module? • 4266 MB/s 15. What are the characteristic features of the Double Data Rate 3 Syn- chronous Dynamic Random Access Memory (DDR3 SDRAM)? • 1 notch on the module contact surface • 240 contact pins • Reads/writes 8 words of data per clock cycle

16. Which of the answers listed below refers to the industry name used for DDR3-1333 modules? • PC3-10600 17. What is the maximum amount of data that can be transferred each second by a DDR3-1600 module? • 12800 MB/s 18. Which of the answers listed below describe(s) the characteristics of Dual In-line Memory Modules ()?

• Printed Circuit Board (PCB) type used as a placeholder for memory chips • Separate electrical contacts on each side of the module • 64-bit data path • Used with various SDRAM memory types (SDR, DDR, DDR2, and DDR3) 19. What is the most common form factor type used in laptop computers? • SO-DIMM

20. Which of the following answers lists the number of pins used by SO-DIMM DDR SDRAM memory modules? • 200 21. DDR2 SO-DIMM memory modules have

• 144 pins • 200 pins 22. What is the number of pins used by SO-DIMM DDR3 SDRAM modules?

3 • 204 pins 23. A memory module form factor commonly used in sub-notebook devices is known as: • MicroDIMM

24. Which of the answers listed below refers to the number of pins used by MicroDIMM DDR SDRAM memory modules? • 172 25. What is the number of pins used by MicroDIMM DDR2 SDRAM modules?

• 214 26. ECC type RAM: • Can detect and correct errors

27. Certain types of RAM take advantage of an additional bit in order to detect whether a data error has occurred. An extra bit is used to store information about the number of bits set to the value of one in a given string of data (typically one byte) and by examining that information at different stages of processing it is possible to detect whether the data has been corrupted or not. What is the name of that extra bit?

• Parity bit 28. Compared to a non-ECC type of memory, the ECC RAM is a less expen- sive option and will always perform faster. • False

29. The color-coded memory slots on the motherboard indicate that the sys- tem is capable of taking advantage of the multi-channel memory architec- ture. • True

30. Which of the following characteristics apply to the type of RAM most commonly used as the main system memory in desktop PCs? • Non-ECC memory • Unbuffered memory • Dynamic RAM

31. Taking advantage of the performance benefits offered by the multi-channel requires: • Memory modules of matching types

4 • Memory modules of matching speeds • Memory modules of the same capacity • Installing modules in appropriate memory slots (slots of matching color) on the motherboard

32. A type of typically more expensive memory modules equipped with addi- tional circuitry designed to ensure better system stability and accuracy of data processing is known as: • Buffered memory • RDIMM

33. A single-sided memory module type can have memory chips placed on both sides of the module. • True 34. Which of the following RAM types would be the most suitable choices for a high-end server? • Buffered memory • RDIMM • ECC memory

35. Which of the memory types listed below allows for permanent storage of data? • DVD-RAM

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References

[1] Dulaney Emmett. Skandier Toby. Docter, Quentin. CompTIA A+ Complete Certification Kit: Exams 220-901 and 220-902. Sybex, 2016. [2] Mike Meyers. CompTIA A+ Certification All-in-One Exam Guide, Ninth Edition (Exams 220-901 220-902). McGraw-Hill Education, 2016.

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