Cross compatable? You mean that you can't play older PS games on a newer system?
Hmm... Let's see:
I'll build a computer with my lousy experience, that ain't very much when it comes to building a computer:
OS: Windows 7 Ultimate (64bit) - Cost: Free (for now)
RAM: 2GB Kingston DDR2 x 4 (8GB RAM) - Cost: 79,60 €
Processor: AMD Phenom II X4 940 - Cost: 177,55 €
Graphics Card: ATI Radeon HD 4870 X2 - Cost: 408,45 €
Graphics Card: NVIDIA GeForce GTX 280 - Cost: 397 €
PSU: Antec Truepower Quattro 1000w ATX - Cost: 163 €
Total Price: 1225,6 € + some for mailing.
Of course you need Motherboard and box for you're computer and those cost few hundred euros more...
If you can build more powerful than this, then do so: Like I said, I ain't any pro with these things but that's what I came up with.
Also, if you buy this, in few years you'll have to put even more money to it... And that keeps going and going.
For console, you just pay it once.
But like said before, PC is more powerful than any of the consoles and has better graphics and you can do lots of other stuff with it as well.
Oh, and why there's two graphics card drivers?
NVIDIA is just because of the PhysX...
:
"You can't install ATI and NVIDIA in a same computer!1!!11"
Yes you can, thanks to Windows 7.