General RAM

Question 1

Single channel vs dual channel

Answer 1

Single Channel: Installed memory shares the same 64bit channel.
Dual Channel: There are 2 separate, colour coded, sets of ram slots (channels). Each channel has a 64bit bus.

Question 2

Parity vs Non Parity

Answer 2

Parity is used for error detection.
Stores an extra bit (parity bit).
Has an extra chip.

Question 3

EEC VS non EEC

Answer 3

Error correcting code.
Similar to parity. Has an extra bit.
Slowest and most expensive
Identified with an E or EEC in the name of the ram.

Question 4

Buffered vs Unbuffered

Answer 4

Buffered has a register between the ram and the memory controller.
Improves the integrity of the signal.
Used for stability when using lots of ram
Identified by a R in the name of the ram.

Question 5

Single Sided

Answer 5

Single sided has a single bank of chips

The memory controller can access all of the chips at once.

Question 6

Double Sided

Answer 6

Chips are divided into 2 banks.

Only one bank can be accessed by the memory controller at once.

Question 7

DIMM

Answer 7

Double Data Rate.
Data is transferred on the rise and fall of the clock cycle
Synchronised to the base clock of the MB
64bit bus

Question 8

DDR2

Answer 8

Decreased voltage to 1.8v
Increased speed through faster signalling.
Requires more pins than DDR

Question 9

DDR3

Answer 9

Not backward compatible
1.2 to 1.5v
???

Question 10

DDR4

Answer 10

1.2 to 1.35v

Not backwards compatible