3.4 Motherboards and 3.5 Power Flashcards
What is RAM used for?
Loading applications and files into a non-persistent and fast storage area
Define cache
High-speed memory
Define Storage
Mass storage device that holds more data but is slower than a cache
What does a disk cache do?
Pulls the files from the disc into memory and replaces the old file
What specifications can an SCMC (Single Channel Memory Controller) come in?
x86, 32 bits, can access up to 4GB RAM
x64, 64-bit, can access up to 32GB RAM
What is the most common type of memory?
DDR (Double data rate), PC133, 133MHz
How is throughput calculated?
Based on the bus speed and the width of the data bus
What is the oldest type of memory (it requires frequent refreshing)?
What type of storage cell does it have?
Dynamic RAM (DRAM)
Dynamic
What was significant about Synchronous DRAM and how many pins did it have?
It was the first memory module to operate at the same speed as the motherboard bus. It had 168 pins
List the three versions of SDRAM.
PC66, PC133, PC266
What doubled the transfer speed of a 184-pin connector SDRAM module?
DDRSDRAM
How many GB/s is PC3-10600?
4.2GB/s
What are the three classifications of SODIMM?
DDR3, DDR4, DDR5
What does DDR2SDRAM offer?
High latency and faster access to the external bus
240-pin connector
PC2-4200, 4.2GB/s
DDR3SDRAM has a throughput of how many GB/s and a maximum module size of how many GB/s per memory module?
Throughput between 6.4 and 17GB/s
Maximum module size of 8GB
Does DDR3SDRAM run at lower or higher voltages and speed than DDR2?
Lower voltage, higher speed
Describe the features of single-channel memory.
- Communication channel between system memory and CPU (system/memory bus)
- “Highway” channel with 64 “lanes” (bits)
Is channel labeling or colour more important?
Channel labeling
Name the three sub-pathways of the memory bus
Data pathway, control (including timing) pathway, and address pathway
What hardware is required for dual-channel memory?
2 memory modules and 2 memory slots on the motherboard
How would you increase the overall capacity in dual-channel memory?
Increase the capacity of the chips (paired chips don’t have to match)
Define how many bits the data bus has for each memory mode (single through quadruple)
Single - 64-bit data bus
Dual - 128-bit data bus
Triple - 192-bit data bus (3 64-bit buses)
Quad - 256-bit data bus
What is the benefit of adding more memory modules?
Gives faster speeds and more memory for storage
What is best practice when using 4 chips in triple channel mode?
Use four chips in two slots and configure as dual-channel to avoid timing issues
What does ECC stand for, and what does it do?
Error Correcting Code
Detects and corrects single-bit memory errors
Describe how ECC works.
There is a ninth chip implemented on the ECC chip to perform parity. This means that for every 8 bits written there is a ninth stored. This is the total number of ones, expressed as an even or odd number.
Then, when the data is read, it is compared against the parity value. If it doesn’t match, the ECC attemps to repair the byte by using algorithms generated when the data was originally written.
Can ECC correct two-bit errors, and why or why not?
No. If there were only four ‘1’s written originally but it corrupted to be 6, the system would not pick up on that as the parity only stores if the number of ones is even or odd.
What is buffered/registered memory?
Additional hardware (register) between memory and CPU. It is used to help reduce the electrical load on the system. This helps improves the reliability and stability of the memory.
What is virtual memory/page file?
Space on a hard drive that is allocated by the OS and pretends to be memory.
When would virtual memory be used?
When RAM is insufficient.
What distinguishes physical from virtual addresses?
The MMU (Memory Management Unit)
What is swapping/paging?
Locating data and returning it to memory
What could excessive paging indicate?
That there is not enough RAM in the system
What is a page file or swap space?
A file that is hidden on a storage device pretending to be system memory
