Help with choosing memory for my PC

[spacesurfer]

Hey, all. I need help with adding more memory to my PC.

I have Gigabyte ga-p35-ds3l with Intel core 2 duo processor. Currently, I have 2 corsair 1 gb x 2 sticks (CORSAIR XMS2 2GB 240-Pin DDR2 SDRAM DDR2 675 (PC2 5400) Dual Channel Kit Desktop Memory).

I want to add 4 GB (2 x 2 GB) for a total of 6 GB for Vista x64 OS. I have 4 memory slots.

Question is: Can I mix 2 x 2 GB and 2 x 1 GB for a total of 6 GB or will I have to have all four of the same capacity?

Another question: I'm looking at Corsair 4 GB right now. Currently, I have PC2 5400 and this is PC2 6400. Does that make a difference in mixing it up?

Thank you all.

[kurbycar32]

im assuming your talking about mixing and matching using dual channel mode. as long as the banks match each other you should be fine. all memory will run at the slowest speed and windows XP32 bit will probably only recognize 3.25gb but i think you already knew that. i doubt you will see any performance difference unless your actually using more than 2gb of ram. my vista install consumes about 1gb of memory on idle, leaving 1gb for programs to hog up. gaming doesnt usually consume it and neither does encoding/decoding videos. if your like me though and you want the memory anyway (i have 8gb and use less than 2) i would pull out the 2 slower chips and just run the 4gb of faster memory, then sell your old stuff. since your not going to see a performance gain in capacity you might as well get the speed increase from the faster DDR.

[spacesurfer]

(Yes, I know Windows 32-bit won't see more that ~3 Gb. I am dual booting Win 32-bit and Vista 64-bit. Reason I'm increasing memory is for Vista's benefit.)

You're saying I won't see a performance gain in Vista x64 by increasing from 2 GB to 6 GB?

I'm not into gaming but I do encode/decode videos.

[bonestonne]

i'm not one for vista, but i can say that you will most likely see a boost in performance with 3x the RAM available.

at my school we have 3 Mac Pros (lets not get into that) but i will say the one with 4gb of RAM owns the one with 256mb of RAM (long story, don't ask).

[kurbycar32]

im saying you wont notice the difference between having the 4 or 6gb so use only the faster ram for a total of 4gb at DDR6400. your actual usage even with encoding videos will be less than 2gb. hook it all up and check your memory usage. if im wrong send me a screen shot of the performance tab of your task manager. my vista machine idles at 658mb ram usage. no real tweaks, i just shut down the sidebar and turned off a few annoying "features"

[spacesurfer]

That was more clear. Thanks.

[spacesurfer]

Humm, after reading http://www.extremetech.com/article2/0,2845,2328804,00.asp, I think there may be a difference, esp if I multi-task with Vega running. Except for gaming, the speed of the memory matters less for multi-tasking.

[bonestonne]

im saying you wont notice the difference between having the 4 or 6gb so use only the faster ram for a total of 4gb at DDR6400. your actual usage even with encoding videos will be less than 2gb. hook it all up and check your memory usage. if im wrong send me a screen shot of the performance tab of your task manager. my vista machine idles at 658mb ram usage. no real tweaks, i just shut down the sidebar and turned off a few annoying "features"

is that 658mb Pagefile usage, or actual RAM usage?....there's a huge difference.

[puntoMX]

Question is: Can I mix 2 x 2 GB and 2 x 1 GB for a total of 6 GB or will I have to have all four of the same capacity?

Strangely, I have had problems* with 6GB on that motherboard and Vista 64bit. With 8GB it works perfectly and 4GB too, so you could be ending up selling your 2x 1GB.

* An example was the card reader that would not read anything from the flashcards.