I plan on getting two 6850s for my future build (i5 760, gigabyte board, 4gb ddr3, etc) but for now I plan on using one of those two 6850s for my old build (D945, gigabyte crap board, 4gb ddr2, 8800gt and etc). How much performance am I losing from pairing the two -- D945 with HD6850?
Playing MW2, StarC2 mostly on 1600x res.
Also, another question is: how much boost am I getting from switching from 8800gt to HD 6850 (with the D945)?
A pretty fair amount. The Pentium D was not even a really good chip even when it was new. BUT since you have it as part of an ongoing upgrade I would not worry about it too much. Most people on these forums are in a constant state of upgrade and do the same thing with one part or another. I just added an SSD although I plan a similar build to what you have listed around the holiday sales.
If you could, can you give me a figure of how much that boost will be? I get around 50-60 fps on cod mw2 (1200x1024) with my current build. Would I get around 60-70 fps on same res if I upgraded the GPU?
The reason why I am asking these questions to begin with is because I plan to build that future computer in the months to come. I have to live few more months with my old crappy build. Also, the 6850s are selling at 160,000 won ($170-$180) each right now. They normally sell for 260,000-320,000 won each.
I would really have to guess especially as the 6850 is such a new card. But I would say yes, at least 60-70 fps if not more. The 6850 is basically between a HD5770 and a GTX460 in strength. That is pretty low resolution as well. If the card is on great sale then get it. It sure will not hurt!