What is a "C-RIMM"

[Degenerate]

I read this

With only 2 RIMM slots for memory, there isn't much room for expansion. However, thanks to Asus and Samsung, a 512Mb module of 32-bit RIMM 4200 was provided for testing. The module was installed and fitted into RIMM slot 1 without any problems. The accompanying C-RIMM was fitted into RIMM slot 2.

What is it?

 

[Wingznut]

Since i850 boards run the RDRAM in serial, if you filled one bank (or a pair of banks) with a stick of RDRAM and left the other banks empty, you would break the serial circuit.

So, they give you CRIMMs with the motherboard. Basically they are just "dummy" sticks used to provide continuity in the circuit.

You must have all RDRAM slots filled for the board to operate.

 

[John]

Each memory slot on the motherboard must be populated in order for it to function. CRIMMs (Continuity Modules) are used to fill slots that do not have RDRAM installed.

 

[Gstanfor]

Basically they are just "dummy" sticks used to provide continuity in the circuit.

I thought "CRIMM" was street talk for a RAMBUS executive...

Greg

 

[Degenerate]

arh I understand now. But how do you buy them?

 

[nightowl]

Usually motherboard makers include them with the board. For example, the Asus board you mentioned has 2 memory slots and Asus would include 1 CRIMM. For a normal P4 RDRAM board there would be 2 CRIMMs included since it is dual channel memory and 2 of the 4 memory slots have to be filled for operation.

 

[dullard]

CRIMMS are available in many online stores (good luck finding one in a B&M store). Pricewatch has them listed as low as $4 (not including shipping). Basically in that board you mentioned, electricity must travel from the MB, to slot 1, to slot 2, and back to the MB. If nothing is located in slot 2 then the circuit is broken and the memory cannot be used.

My question is this: people often claim that replacing the CRIMM with a regular RIMM will add latency since electricity must travel through slot 2. But since a CRIMM already has it running through that slot why would it slow down? I get the same memory benchmarks with 2 RIMMS/2 CRIMMS as with 4 RIMMS. Basically I think people are talking without knowledge.

 

[Wingznut]

Originally posted by: dullard
Basically I think people are talking without knowledge.

Yeah, that pretty much sums it up.

 

[Athlon4all]

Thats an interesting way of thinking of it dullard.

 

[Jmmsbnd007]

RIMM terminator.