Will 400 mhz DDR memory work in most 266 fsb systems?

[techmaster98]

At work I got in a discussion about this with colleagues. We were going to order memory to upgrade older computers (some run on 266 bus, others 333 bus)

From what I understand new memory will work just fine in older systems, it will just downclock to the bus speed. (In my experience this has been the case) I figured we might as well get PC3200 ram then, that way we could even use it in some of our newer systems if we wanted to (that use 400 fsb). However a coworker of mine disagreed and voted for the PC2700 memory, since we'd face less compatibility issues with the older systems he says.

But the fast memory should work just fine in old systems, right?
I thought the only upside to ordering slower memory was the cost savings. Or do slower chips work better in some older systems?

 

[Bobthelost]

It should work fine, there is the possiblity that the RAM controllers will only be capable of lower RAM densities, but i think that was only ever really a problem for really old systems (ie DDR 133 era) even then it tends to work fine, but you can only use half what the stick should provide.

 

[techmaster98]

Originally posted by: Bobthelost
It should work fine, there is the possiblity that the RAM controllers will only be capable of lower RAM densities, but i think that was only ever really a problem for really old systems (ie DDR 133 era) even then it tends to work fine, but you can only use half what the stick should provide.

heh, i figured that was the case.
so basically density has been a non-issue since those days, eh (and u mean SDR not DDR, right?

 

[xgsound]

In extreme cases, either way can have compatibility problems. I would think that voltage requirements would be the most likely to cause problems if the computer bios doesn't allow voltage adjustment. Some bioses don't allow speed adjustments either and may only use the SPD of the memory. In cases of difficulty, these machines may not post at all with incorrect memory unless the bios is preset acceptably while the old memory is present.

It's a great idea to get one kind of mem for all the upgrades, but that may not be possible. I would get a quantity a little less than you need and start with the machines most likely to be troublesome. If some don't work, go to the crucial or corsair sites for those machines to determine specifically what's compatable.


jim

 

[memories2002]

Ive done it, works fine.

 

[techmaster98]

any difference if I choose to use double sided or single sided dimms, in the older board?