You could try 4gb + 2gb
I think the only issue with mixing RAM is timing, I think different sizes are fine if it's the same timing
It's 3GB max
per DIMM, so I can't put a 4GB stick in it, otherwise I'd already have done that, seeing as I have two 4GB DIMM's that I still can't even use.
I don't need it anyway, I just want to know if anyone's seen a 3GB DIMM.
And neither timing or size matter specifically, so long as the motherboard supports it.
If you put two sticks of different speeds, it's clock down to the lowest speed. (Assuming they didn't forget up the BIOS.)