New ram, and combonations?

[Alan00000]

I just installed my new ram which is 2x2gigs sticks =4 gigs PC6400 , can i use my old PC6400 in the other open slots ? they are 1 gig sticks though would it slow it down or be faster?

 

[VirusType2]

You can mix RAM sizes like: 2GB x 2, 1GB x 2. If they are the same speed, it will simply give you more RAM and it will stay dual channel. However, if they are different speed/timings, it will use the slower speed and/or timings for all of the RAM. Not sure about timings, actually, but Mhz, definitely.

If your BIOS is any good you should be able to view and change the timings. RAM often needs to have the timings configured correctly in your BIOS. My RAM timings were set slower than the capability of the RAM when I first installed it, so I set it to the advertised specs of the RAM and was done with it.

 

[Alan00000]

Thanks