Question on RDRAM's matching pairs...

[Random Person]

If I have a 128MB PC700 RDRAM module on an old comp and an empty slot
filled with a spacer, exactly how for do I need to go with the
"matching pairs" rule? Do I need to get exactly the same brand, the
same FSB and the same size?

PC700 RDRAM is quite rare, and I think I'll be lucky if I can get PC800
at an acceptable price.

 

[Random Person]

Also, what is ECC and do I need to match that as well?

Are the matching requirements at the motherboard or module level? (i.e.
must I get PC700 ECC RDRAM if my previous one was that because my
motherboard won't accept anything else?)

 

[ElJerid]

Also, what is ECC and do I need to match that as well?

Are the matching requirements at the motherboard or module level? (i.e.
must I get PC700 ECC RDRAM if my previous one was that because my
motherboard won't accept anything else?)

The rule is to use matched pairs. Same manufacturer, same type, same speed.
Although some motherboards are more "relax" in handling ram bars and could
work with "some" unmatched pairs, but still at the lowest common speed.
ECC stands for error check and correcting.

 

[philo]

If I have a 128MB PC700 RDRAM module on an old comp and an empty slot
filled with a spacer, exactly how for do I need to go with the
"matching pairs" rule? Do I need to get exactly the same brand, the
same FSB and the same size?

PC700 RDRAM is quite rare, and I think I'll be lucky if I can get PC800
at an acceptable price.

you generally do need "identical" pairs...

you should be able to find what you need on ebay at a reasonable price...

also...even if you have an extra , odd stick...
more than likely you will be able to sell it on ebay!

i was able to sell (individually) some non-matching RAM...
just...for the sake of honesty...if you go to sell it...mention
that it generally needs to be installed in matching pairs

 

[Michael C]

If I have a 128MB PC700 RDRAM module on an old comp and an empty slot
filled with a spacer, exactly how for do I need to go with the
"matching pairs" rule? Do I need to get exactly the same brand, the
same FSB and the same size?

PC700 RDRAM is quite rare, and I think I'll be lucky if I can get PC800
at an acceptable price.

Sell it. I accidentally bought a second hand PC that had 256MB of rambus
memory. A new motherboard cost me $65 and new DDR ram was about $32. I got
$91 for the old ram and motherboard on ebay so it cost $7 to change over.
But upgrading from 256MB to 512MB I saved about $50 and had some new parts
in the PC.

 

[DaveW]

Yes, they have to match. You'll probably have to buy a PAIR of PC800 if
you're trying to increase your RAM.

 

[Paul Murphy]

If I have a 128MB PC700 RDRAM module on an old comp and an empty slot
filled with a spacer, exactly how for do I need to go with the
"matching pairs" rule? Do I need to get exactly the same brand, the
same FSB and the same size?

PC700 RDRAM is quite rare, and I think I'll be lucky if I can get PC800
at an acceptable price.

If your machine is currently running fine with a single RIMM and a
Continuity Module installed in the second slot you will NOT have to install
a pair of RIMMs but if you do want to upgrade the memory my suggestion is to
sell the old module and buy a new one of PC 800 spec in the capacity
required. Its a common myth that all PCs must have RIMMs installed in
pairs - it depends on the chipset/design used and some older motherboards
(eg my Intel 820 chipset Pentium III) work quite happily with 1 RIMM as long
as a continuity module fills the other slot for that bank. If you want to
add a new RIMM to the existing one however it would have to be a matching
unit in every way (and this would be very difficult to find). Although you
wont get much for your lone old module secondhand, you can pick up a new
single module quite cheaply on eBay from people who've had one module die on
them or from some memory specialist shops that use eBay - thats what I did
and 512 MB in a single RIMM worked out just over half the price of a
matching pair of 256 MB RIMMs. You just need to find someone who has an
"odd" RIMM to sell.

Paul

 

[Random Person]

Thanks guys. Your input was much appreciated.