[tallen0]

I'm upgrading my RDRAM and I don't know if I should be purchasing ECC or Non-ECC. Also, the site that I'm purchasing them from lists some as "40ns" and others as "45ns", does it matter which one I purchase? (Because the 40ns are ten dollars more expensive.)

I currently have a pair of 64MB sticks (that originally came with computer), and a pair of 256MB sticks (that I purchased later, the guy at the store just gave them to me and they worked).

I'm planning on replacing the 64MB's with another pair 256's.

I don't know if it matters but, CPU-Z lists the 64's as:

PC600-53 (300 mhz)

and the 256's as:

PC714 (357 mhz)

I know very little about this stuff so if I left out some necessary piece of information please tell me, and thanks in advance for any help.

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Ooh, somebody with RDRAM. Haven't seen that for years.

if a mainboard has a dual- or quad-channel memory subsystem, all of the memory channels must be upgraded simultaneously. Sixteen-bit modules provide one channel of memory, while 32-bit modules provide two channels. Therefore, a dual channel mainboard accepting 16-bit modules must have RIMMs added or removed in pairs. A dual channel mainboard accepting 32-bit modules can have single RIMMs added or removed as well.

What is your motherboard model please?

[Neil Jones]

Ooh, somebody with RDRAM. Haven't seen that for years.

if a mainboard has a dual- or quad-channel memory subsystem, all of the memory channels must be upgraded simultaneously. Sixteen-bit modules provide one channel of memory, while 32-bit modules provide two channels. Therefore, a dual channel mainboard accepting 16-bit modules must have RIMMs added or removed in pairs. A dual channel mainboard accepting 32-bit modules can have single RIMMs added or removed as well.

What is your motherboard model please?

[tallen0]

Thanks for the reply.

Regarding the RDRAM. Yeah, I know it's old. This computer is 10 years old, but it still works (barely).

I'm pretty sure that I have a board that you have to replace memory in pairs (at least that's how I added the two 256's).

CPUZ lists my motherboard as:

Hewlett-Packard
HP WMTA System Board 123

(I'm not sure if that's the info you're looking for so if it's not just tell me.)

Thanks again.

[Neil Jones]

All RDRAM systems have to be upgraded in pairs.

Googling for HP WMTA System Board 123 would suggest from a post that the machine will take PC800 memory. However HP and other manufacturers would have made thousands of these RDRAM capable boards and the model number listed is probably generic.

In theory your PC714 should throttle it down back to the slower speed, or at least that's what happens with mainstream DDR. However in practice this stuff should ideally be matched to the existing stuff. That being said as well, RDRAM memory isn't cheap. Last time I looked at it it was far more economical just to simply replace the board and the memory, especially on a ten year old machine.