I have a similar scenario which I like to ask this forum. I have a ASUS A8V Deluxe m/b with Athlon 64 3700+ (socket 939). I have 2x512MB Corsair XMS DDR400 (2-2-2-5 timing) memory modules installed in bank 1 and 3 in dual-channel configuration. I've been running this configuration for quite some time.

Recently, I acquired some Patroit Signature Series 2x512MB DDR400 (2.5-3-3-7 timing) memory and I like to add the extra 1GB to my system.

I tried the following configurations, none of which worked. Either I see only 1 GB or the system won't boot up:

1) Corsair in bank 1+3, Patroit in bank 2+4
2) Corsair in bank 1+2, Patroit in bank 3+4
3) Patroit in bank 1+2, Corsair in bank 3+4

My memory settings in the BIOS are set to AUTO.

Can I use the memories with different timings in my system? Or do I have to use all 4 banks of memories with same brand/type/timing?

hi i just joined this forum and ive read all about dual channel. and my question is the same as the post above me. ive had 2x256pc3200 in my system, which i figure were running in dual channel already because they came in slots 1 and 3 (both colored black). anyway i just bought 2x512 corsairpc3200 recently and i put them in slots 2 and 4 (both white). my question is can you have 4 dimms running in 2 separate dual channel (one dual channel in the white and one in the black) or do all 4 sticks have to be the same capacity and speed? if so, should i take out the 2 sticks of 256 and just run with the 1gig of corsair? or leave the 1.5gig? what will run faster? thanks

EXACTLY my question. Will 4 sticks run as 2 in each channel

You can go dual channel ,, .. sorta like a freeway,,

more lanes,, more cars can pass,,

Not necessarily. In general it is best to stick with 2 sticks. Most motherboards work best with 2 sticks of ram because voltage drops off when you add more sticks in parallel. There are some mobos out there than accept more than two and run dual/multi channel. I have an MSI board that runs in TRI channel.

By and large it is best to stick with TWO sticks of RAM.