Help, Mixed DDR

I have 2 modules of DDR, different speeds and timings, both 512Mb in size. One is DDR400 @ 200Mhz, CAS 3 by SPD (Nanya). The other is DDR266 @ 133Mhz, CAS 2.5 by SPD (SpecTek). I'm not sure what timings I should run them both at, or in witch slots, currently 1 and 3. Both are timed at 2.5-3-3-7-9-16, it's what I manually set them in BIOS. Any help would be appreciated as I would like to have a gig of RAM but I'm too poor to run out and get a matching pair. I slap in one or the other they work flawlessly, I slap in both and my PC get's a little jumpy now and then. I'm new to this stuff and am willing to learn.


AMD Athlon 64 3000+ "NewCastle" (DH7-CG)
MSI K8T Neo FIS2R
1024Mb RAM, 2x512Mb
Windows XP Home/SP2
Nvidia GeForce FX 5700LE
And some more stuff too

doesn't really matter what slots you run them in seeing you can't have dual channel with a socket 754 a64.

Thanks for the reply. I'll try to tweak with the timings some more and see what happens.

welcome to the fourms!!!!!! theres a big difference in memory capability between pc2100 and pc 3200.unless the pc2100 really overclocks well i wouldnt bother with it cause u could lose alot of bw if u have to run it at pc2100 speeds