Will these 4 DDR sticks work together?

[360bhp]

Currently have 2 x 2gb of OCZ DDR2 PC2-6400 Gold GX XTC Dual Channel 1.8V - CL 5-5-5-15 (CAS-TRCD-TRP-TRAS)

If I had another 4GB of: OCZ Gold 4GB (2x2GB) 1600 MHz PC3-12800 1.65V - CL8-8-8-24

Will this work ok?

[chuckskull]

No, the PC3-12800 kit is DDR3, your current ram is DDR2. For DDR3 you'll need a new mobo and CPU, which in turn won't not work with your DDR2.

[360bhp]

Sorry, didn't realise it was DDR3. Thanks.

What about PC2-8500 / 1066MHz - CL 5-6-6-18

[chuckskull]

Yes, PC2 = DDR2 and PC3 = DDR3, I would recommend another set of PC6400 though, save you a few quid, as you wont really gain anything from the higher speed ram as it will only run as fast as the slower RAM anyway. The performance difference is negligible between the two speeds anyway.

[360bhp]

Thanks.

Edit: Does the latency or voltage have to be the same?

[chuckskull]

No problem.

[Biscuit]

Thanks.

Edit: Does the latency or voltage have to be the same?

Latency, no probably not. Leaving it on automatic settings should just set it low enough for it all to work although if you have to manually put it in then go for the slower latencies.

Voltage, yes! Im guessing your mobo wont let you set individual voltages per stick so its wise to match them.

[chuckskull]

Yeh you can get away with running the sticks at a slightly higher voltage but ideally you'd want another 1.8v set, but that's the standard voltage for DDR2 so you shouldn't have any trouble finding some.