rdram/ rambus matching

[Rbot]

:confused: Hi,

I've got a PIII with one Samsung 128 MB (700Mhz) rambus stick.
(the second RIMM has a continuity circuit installed)

I would like to upgrade this PC to at least 256 MB ram. But I'm wondering if the second RIMM will have to be Samsung as well, or could it be made by a different company?

Also would the second RIMM have to be 128 MB? Or can you mix them up?

For example,

Rimm 1 = 128mb 700Mhz (Samsung)
Rimm 2 = 256mb 800Mhz (OEM, or whatever)

or even:

Rimm 1 = 128mb 700Mhz (Samsung)
Rimm 2 = 256mb 700Mhz (Samsung)


Would the system still work? How closely do they have to match?

Thanks all. Would really appreciate any help. :)

[saphalline]

Well, on a PIII system using RDRAM, you've got Intel's ill-fated i820E chipset. Not a bad chipset, just not really all that popular. However, unlike a P4 where the RDRAM must be used in pairs, you've got some freedom here. Install your sticks of RDRAM however you want, using PC600/700/800 RDRAM, up to a maximum of 1GB total.

Be aware, however, that in mixing and matching, the speed of the RDRAM will be set to the slowest one, so if you add a stick of PC800, it will run at PC700 speeds in order to keep back with your current stick of PC700.

Oh, and hang onto that continuity module! Never know when it might come in handy... ;)

[Rbot]

Saphalline,

I appreciate the info.

The problem is that rdram is so expensive. Plus my MOB
will only take a maximum of 512mb (and according to
the IBM support site that can only be achieved on this
particular machine with two sticks of 256mb PC800 rimms -

http://www-1.ibm.com/support/docview.wss?uid=psg1MIGR-4ESSC7
[see note under table]

..ouch !*#@! that's well over $250.00 before taxes)

so it really isn't worth it (cost-wise) to get it up to the max,
since i'd rather invest the money in a new system.

However, your advice is well taken. Right now I would just like
to jack up the ram a litte so I can keep the pc around for a while.

Cheers