Anything wrong with using different ram sticks?

[dds14u]

I don't really know much about computer hardware, and I was just wondering if there would be any type of bottlenecking, or underperformance caused by using say, a 512mb RAM stick and a 256mb RAM stick...rather than two of the same, what if they were from two different manufactuers? Thanks.

 

[Navid]

There is nothing wrong with using different sticks of RAM as long as you don't want dual-channel performance.

If you want dual-channel, you need to have the same size sticks. The addressing of the two moduls should be the same too. You cannot use a single-sided module with a double-sided module, even if they are the same size.
Preferrably, you want them to be identical. But, that is not a must.

Edit:
Of course, if your motherboard does not offer dual-channel, then, you have nothing to worry about.

 

[Algere]

You'll be limited by the slowest of the 2 memory modules in terms of performance

e.g. If ram stick A can run @ DDR400 operation while ram stick B is limited to DDR333 operation in the same machine @ the same time. Both would run @ the speed of the bottleneck, in this case, ram stick B.

 

[Concillian]

Originally posted by: Navid
If you want dual-channel, you need to have the same size sticks.

Not necessarily, I mean it's preferred yes, but you can run 512 paired with 256 and still get dual channel performance (on 512 of it anyway) For instance I have run 2x 256 MB in one channel and 1x256 in the other of my nForce2 board. The BIOS reports dual channel, and SiSoft bandwidth and SuperPi results indicate it was indeed dual channel.

Also 2 single sided 256 with 1 double sided 512 works well in my board.

 

[Navid]

Originally posted by: Concillian

Originally posted by: Navid
If you want dual-channel, you need to have the same size sticks.

Not necessarily, I mean it's preferred yes, but you can run 512 paired with 256 and still get dual channel performance (on 512 of it anyway) For instance I have run 2x 256 MB in one channel and 1x256 in the other of my nForce2 board. The BIOS reports dual channel, and SiSoft bandwidth and SuperPi results indicate it was indeed dual channel.

Also 2 single sided 256 with 1 double sided 512 works well in my board.

You are right. But, the original poster was not asking about three-stick configurations, I don't think. He was asking about pairing TWO sticks. In which case, you have to have them to be the same size.

Edit:
This is specific to Intel:
http://www.kingston.com/newtec...F_520DDRwhitepaper.pdf
But, it gives a good introduction to the idea and the limitations of DDR. See page 9.

 

[dds14u]

Alright hehe thanks, so bottom-line is it's definitely better to use two of the same exact sticks :laugh: hehe.

 

[Zebo]

No it's better to use one single sided stick

But ya..You'll be limited by the slowest of the two.