RAM Flashcards
SDRAM meaning?
Synchronous Dynamic Random Access Memory
SDRAM are identified how?
2 notches and 168 pins
DDR meaning?
Double Data Rate
DDR modules are identified how?
“PC-“ on module and 184 pins
DDR2 modules are identified how?
“PC2-“ on the module and 240 Pins
DDR3 modules are identified how?
“PC3-“ on the module and 240 pins
SO-DIMM modules are identified how?
Shorter for laptop with 204 pins
DDR4 modules are identified how?
“PC4-“ on the module and 288 pins
What is MT/s
Mega Transfers per Second
The rate at which transfer happen in and out of RAM
Given the Clock speed of DDR4 RAM how do you work out the PC rating?
MHz x 8 = PC speed
DDR and PC ratings relate to what?
The speed rating of RAM
Given the PC rating of DDR4 RAM how would you work out the Clock speed of a module?
PC rating / 8 = MHz speed
184 pin module is what class of DDR?
Just DDR
240pin module is what class of DDR?
DDR2 or DDR3 which would be identified by the “PC-“ rating of 2 or 3
288 pin module is what class of DDR?
DDR4
What type of module has 204 pins?
SO-DIMM for laptops.
RAM is avilable in single and double sided but what feature does this refer to?
what must be checked?
Chips on one or both sides of the RAM module.
If the motherboard supports it.
What are “Channels”?
Specific paired or grouped slots that are optimised together.
Dual, Tripple, Quad channel memory allows the system to do what?
Simultaneous access to multiple modules.
What is a must be use in order to allow RAM channels to function as designed?
Identical modules that are normally sold in paired/grouped packs.
What does SO in “SO-DIMM” mean.
Small Outline, for laptops.
What is Parity RAM?
Can detect a singe failure. Cannot correct the failure.
Typically 8 chips.
ECC RAM description.
EEC - Error Correction Code.
Can detect multiple failures, typically 2. Can correct a single failure.
Typically 9 chips
What type of Ram can detect a singe failure but cannot correct the failure.
Typically 8 chips.
Parity RAM.
What type of RAM can detect multiple failures, typically 2 but can only correct a single failure.
Typically 9 chips
ECC (Error Correction Code) RAM description.
How many chips can go bad in Parity and ECC RAM?
1 in Parity, 2 in ECC
What is an SPD chip?
Serial Presence Detect chip, holds the RAM spec and defaults for the motherboard to detect.
What do we check before buying or installing RAM?
Motherboard spec and manual for:
Capacity,
Speed,
Which slots to use for channels,
If Parity or ECC capable.
What holds the RAM spec and defaults for the motherboard to detect.
SPD chip, Serial Presence Detect chip.
What programs can be used to diagnose RAM?
Windows Memory Diagnostic tool,
MemTest86
