CPUs and RAM 1101

What three characteristics are true about SRAM and DRAM?

• SRAM and DRAM both need to be refreshed with the same frequency

• Both are considered volatile because they only hold data while power is on

• SRAM is faster than DRAM because it does not need to be refreshed

• DRAM is closer to the CPU than SRAM because it has a 64-bit data path

• The type of memory used in a memory cache is SRAM because it is faster

An organization wants to increase the amount of RAM on their computers. All the computers have four memory slots but only two slots in each computer are populated. They want to add one more memory module to the older computers, and two additional modules to the newer computers. The older computers have three blue slots and one black slot. Which memory type will maximize the number of DIMMS the memory controller can access at the same time in both, the older and newer computers?

• DDR

• DDR2

• DDR3

• DDR4

Answer explanation

DDR3 DIMMs can use quad, triple, or dual channels. Installing two additional DDR memory modules in the newer systems will allow it to operate in quad channel mode. Since the older computers have three blue slots, add the third memory module in the blue slot, and leave the black slot unpopulated. This allows the DDR3 DIMMS to use triple channels.

DDR4 DIMMs can use dual or quad channels

A computer has four DDR4 memory modules. Two modules have a speed of 3000 MHz and the other two have a speed of 4000 MHz. If the two 3000 MHz DIMMs are upgraded, the new modules to be installed should have what rating?

• PC4 24000

• PC4 25600

• PC4 28800

• PC4 32000

Answer explanation

PC4 32000 corresponds to a speed of 4000 MHz (4000 x 8 = 32000). Since only the slower modules are being replaced, you will want to match the speed, type, and manufacturer of the faster modules to achieve a performance gain.

Tomi buys a CPU from a computer store. The retail box references the amount of L1 cache in the list of features. What is it referring to?

• The maximum amount of memory the processor can access

• The memory in the CPU package, but not on the processor die

• The amount of memory residing directly on the processor die

• The memory between the CPU package and the DIMM slots

Answer explanation

L1 is the amount of memory on the processor chip (die) itself. It is faster than RAM and typically in the order of Kilobytes per core.

A system administrator boots a Windows PC using a Live Linux CD/DVD and list the files on the system. One of the files is called pagefile.sys. What is this file used for? Select all that apply.

• Windows normally stores virtual memory in this file.

• Windows stores filesystem information in this file.

• Used to enhance the amount of RAM in the system

• It is a type of cache to backup up the contents of UEFI

• Mirrors the contents of RAM to improve performance.

Answer explanation

Pagefile.sys is a hidden file in the C: drive. It stores data from RAM that is not accessed frequently. The goal is to free up memory in RAM for additional data that is frequently accessed.

A field service technician is replacing a server motherboard that supports CPUs with multithreading capabilities. The technician notices the motherboard has four processor sockets. If each socket supports a quad-core processor, how many logical processors does the system appear to have?

• 4

• 8

• 16

• 32

Answer explanation

The system can accommodate four processors. Each processor has four cores. Each core, using multithreading, can handle two threads so each CPU appears to have eight logical processors. Thus, the total number of logical processors is 32 (4 CPUs x 4 Cores per CPU x 2 threads per core).

For maximum efficiency and performance, a highly tuned and specialized application needs to run on a system capable of handling exactly 16 threads at the same time from the operating system. Which two of the following will best meet the specified requirement?

• A motherboard with four dual-core processors

• A system board with two quad-core processors

• A system with a 64-bit operating system installed

• A system board with four quad-core processors

• A motherboard with two 8-core processors

Answer explanation

The number of threads is determined by multiplying the number of CPUs times the number of cores times 2 (each core can handle two threads). 4 CPUs x 2 cores x 2 threads = 16.

Jenny is working on a laptop computer and notices that the computer is not running very fast. She looks and realizes that the laptop supports 8GB of RAM and that the computer is running only 4GB of RAM. Jenny would like to add four more gigabits of RAM. She opens the computer and finds that there is an open slot for RAM. She checks the other module and determines that the module has 204 pins.

What module should Jenny order?

• SO-DIMM DDR

• SO-DIMM DDR2

• SO-DIMM DDR3

• SO-DIMM DDR4

Answer explanation

SO-DIMM DDR3 has 204 pins. The amount of data transferred using DDR 3 per second can range from 8.5GB to 14.9GB, depending on the speed of the FSB (front-side bus).

You are researching RAM for a computer you are building for a friend who will be using the system as a home office server for a small business. She wants the added protection so the computer will not crash due to a memory error.

What type of RAM should you consider purchasing?

• Unbuffered

• Buffered

• ECC

• Registered

Answer explanation

ECC compares bits written to the module to what is later read from the module and detects and corrects errors in a single bit but only detects errors within 2 bits.

You are reviewing new RAM to purchase for a gaming computer and find three different RAM modules that are the same except for their CL rating.

The memory with which rating will work best?

• CL15

• CL18

• CL20

• They will all perform at the same speed.