Same speed, different cap memsticks?

[Moozillaaa]

I have 2 1G 667 sticks in channel 1 DIMM slots.

Can I put 2 2G sticks, exact same manufacturer / speed / chipset ID in channel 2 DIMM slots?

Mobo supports 8G max, 1066 speed...

If so, will there be ANY downside?

Or maybe a 1G and 2G in each channel?

[cascade9]

Yes, you can run different sized/speed RAM sticks. The RAM will run at the lowest speed though, so you might be better off just removing the 2x1GB DDR2 667 sticks and just using 2x2GB DDR2 800/1066.

That will depend on your RAM usage, but in most cases, 4GB is more than enough.