new cruncher coming soon

[r2d2]

Once I get the computer, I'm gonna open it and look.. If it is 2 4's and 2 2's, I may just pull the 2's and add 2 more 4's to give it the 16 gigs.. I'll see how it runs and if not happy I'll make the change. I'm anxious to get it and get it crunching.. Should boost my RAC on pogs nicely...

[DrPop]

I think it will be fine if the two 4gb DIMMs are on the same channel, and the two 2gb DIMMs are on the other channel. If they are different speeds, the while thing should work at the slower speed.

I agree, what Zombie proposed will work. Make sure you put the 4GB sticks in the "first" slots (actually DO read the page in the manual of the motherboard because they are all marked a little differently, like A1, A2, etc) and put those 4GB sticks in the pair of slots that the manual says to use if you only have two sticks total. That will give you best performance.
Then, populate the remaining two slots with those 2GB sticks, and the computer will use up the 8GB on the two bigger sticks first (one on each channel), and then if ever it needs more, it will dip into the smaller sticks.