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I have an Asus M2N-E motherboard, currently with (qty 1) DDR2 module Kingston KVR533D2E4/1G. The board has 4 total slots.

Going to upgrade and I'm wondering if I can mix sizes -- can I add a 2G module and keep the existing 1G?


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up vote 4 down vote accepted

Yes. You can have different sizes, and even in most cases, different speeds (Not suggested though). The only thing to really look out for is that they are compatible. If you're putting in the same brand/model, just different size, I wouldn't see a problem.

EDIT: This may also be helpful: Can I mix and match RAM?

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Yes, I'm going to put in the same model just sized up: KVR533D2E4/2G. Thanks! – bstpierre Nov 13 '09 at 15:24
I may have added an edit after your comment... Hopefully you noticed the attached link. – Sivvy Nov 13 '09 at 15:26

You can. However, do notice that on dual-channel memory board, this will decrease memory access speed.

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Thanks for the advice. Is it a severe penalty? I was going to install a single 2G module @ 533, but if the mixture is going slow things down, maybe I'll dump the 1G and get 2x2G @ 667 or 800... – bstpierre Nov 13 '09 at 16:49
Not a severe penalty, but in order to have Dual Channel, both sticks need to be nearly identical (Size and speed). Mostly what you'll be losing out on is the additional bus bandwidth. It's nice, but its your choice if you want 3Gb or faster 2Gb or 4Gb. DDR2 is cheap these days. – Sivvy Nov 13 '09 at 16:54
I'm getting to where I end up hitting swap on a daily basis, which is painful -- have to go through and prune out processes that aren't in active use... I think even "slow" 3Gb will not hurt too bad. – bstpierre Nov 13 '09 at 18:48
I'd just go to 3Gb, then upgrade to 4Gb as soon as you can. 32 bit Windows will only use a little over 3Gb, but the Dual Channel is helpful, and it isn't really a waste, since the kernel still gets to access the additional RAM for hardware/BIOS stuff. – Sivvy Nov 13 '09 at 19:50

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