RDRAM......to pair or not to pair?

[G14]

The following was taken from the Anadntech article "Pentium 4 1.4 and 1.5ghz" in regard to RDRAM configuarations :

"..however it requires that you install RIMMs in pairs of two...."

I've been hearing conflicting reports as to weather or not you HAVE to pair them. A buddy of mine that I buy hardware off says that you don't have to pair them. I've heard this from a few other places as well including a couple of online resellers (not that I have faith in them)

Does have anyone know for sure one way or the other?

Thanks in advance.

 

[jimmygates]

I believe you have to pair them for P4's



-Jimbo

 

[Dulanic]

P4 is Dual Channel... you have to use pairs.

 

[Bignate603]

you don't have to pair, but you need a special thing that goes in the slot instead of a RIMM if you don't want to make a pair. The name escapes me but i've seen them. Theyhave no memory but theymake the board accept that it does not need a pair. You cannot run a single RIMM without one of these.

 

[Czar]

To burn or not to burn, that is the question.

 

[Jumpem]

I've read of a P4 being run with only one RIMM(single channel), but performance was cut quite a bit. Don't remember which hardware site it was though.

 

[toph99]

they're like SIMMs i believe, have to pair them

 

[Bignate603]

I think i remember the name, they called the things blanks in the website i was looking at. It looked like a really short RIMM made with blue plastic where the memory chips would be.

 

[Pariah]

P4 systems require pairs, which why retail P4's include 2 64MB RIMMS, not 1 128MB RIMM. P3 systems do not need pairs, but they still need blanks to fill the slots that have no RIMMS in them for the system to work properly.

 

[Schola]

If you are not puting a stick of ram in one of the slots then you need what is called a continuaty(sp) rimm.

 

[odog]

it's not the cpu that dictates weather you need a pair of RIMMS.. it's the chipset the i850 is a dual rambus channel design, hence it needs 2 sticks to work(just like the i840 needs 2)

what you friend is prolly thinking about is i820 which is a signal channel rambus design... and along with it's bad performance w/ sdram.... can also be used with a single RIMM

the continuity moduals i believe have to do with the serial memory design... and the way that the rambus design routes the data thru both RIMM slots... without the "blank" in there, the data hits a dead end.

 

[G14]

Thanks for all your help guys...I belive Bignate603 and Jumpem were correct...I found the following over at Gateways support site.

"If your computer uses RIMM system memory, you need to use a combination of Rambus Interface Memory Modules (RIMMs) and Continuity-RIMMs (C-RIMMs). All memory slots must be filled with either RIMM or C-RIMM. C-RIMMs are placeholders that let the memory modules work. A C-RIMM does not have a metal cover on either side of the module........If you are installing one memory module, install the RIMM in RIMM Bank 0 and the C-RIMM in RIMM Bank 1 on the system board."

The last sentence there implies that you can add just one RIMM. I'm assuming that since the PC comes with 2 64mb RIMMs that it would have the C-RIMMs already in the other two slots allowing me to simply remove one of the C-RIMMs and add one 128 meg stick.

 

[G14]

Any chance of Anandtech modifying their P4 article with the correct information?

 

[Bignate603]

very true, anandtech should keep up with the current info, i'm wondering how much of a hit you take when you use a RIMM and a C-RIMM like it was calledat that gateway site.

 

[Redwingsguy]

I think you can use 1 strip if you have a terminator