1 stick vs 2 sticks

[stefan238391]

I was going to buy 2x 1GB DDR2-667 for my new Core 2 Duo E6400. That was the plan about a 2 months ago. Wait for the CPU and mobo to become available and get it. Now... RAM prices seem to have gone up, and the 2GBs don't really fit my buget anymore. I was thinking to get 1x 1GB stick and get the other 1GB in one, maybe two months. Otherwise I'd have to go from GF7900GS to GF7600GS... Or 19" to 17" LCD... NOT an option.

My question is: is there a big difference in performance between 1GB DDR2 and 2x 512MB DDR2 running dual channel? Is it like 5-10%, or more like 40-60%? If I get the 2x 512MB, my memory config will be messed up when I have to get another GB for Vista.

Also, if I get one 1GB and another 1GB later, identical, will they be able to run in dual channel mode? Or is it just the kits that work that way?

 

[jaguarskx]

Using only 1 stick of RAM will probably decrease performance about 10% or 15% depending on the application. I would just go for the 1 stick of RAM and the 7900GS/19" LCD. Buy the additional stick of RAM (same make and model) when you have the money.

 

[Mondoman]

...
My question is: is there a big difference in performance between 1GB DDR2 and 2x 512MB DDR2 running dual channel?

There could be for memory-intensive programs. Your C2D CPU can accept data from memory at 1066MHz. In single-channel mode, your DDR2-667 can only supply it at 667MHz; in dual-channel mode it can supply it at 1333MHz, more than enough to saturate the CPU FSB.

If I get the 2x 512MB, my memory config will be messed up when I have to get another GB for Vista.

Why? Just get 2x512MB for around $100 now (good DDR2-667 CL4 here: http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=85002-51) and get 2x1GB more (total 3GB) when Vista comes out and memory prices are cheaper.

Also, if I get one 1GB and another 1GB later, identical, will they be able to run in dual channel mode?

Yes and no. If they really are identical or very similar, dual channel mode should work fine. However, manufacturers are constantly making changes to their DIMMs, so the DIMMs two months from now, even with the same model number, will NOT be identical to those of today.