I have dual 4850x2's in one system and 3 GTX280s in another system. The 4850x2's are the best cards I've ever owned and the two of the perform just as well as the 3 280s with a whole 1 gig of extra onboard RAM. And they run with fat over clocks, 700mhz per core, the 280s run at 730mhz max OC. The 4870x2 barely outperforms the 4850 and the price is much higher. I would love to have a 4890 x2 but the price will be outrageous. The 4850x2 is cheap for what you get, buy two of them but make sure you got over 1000 watts to push em, or a good 1000 watt. I run em with a 1000 watt Cooler Master Real Power Pro. And the 280s run with a 1250 watt Cooler Master. So think about it, $1000 or more for dual 4890x2s or $450 for 2 4850x2s. Unless you're obsessed like me get the 4850x2 it's amazing. The GDDR5 RAM isn't to the point yet where the performace gains are great enough to warrant spending almost double. Let's see, 2300mhz that's what I run mine at or 3600mhz for the 4870s on average maybe 5 FPS more. Save your money. Also the 4850x2 comes with a bunch of really cool software that you could sell to one of your buddies to get back the dough you spent, since you'll have two you only need one of each. BTW, running 1920x1200, AMD Phenom 940 OC'd to 3.76 ghz with Corsair Dom. DDR2 1066 mhz, Gigabyte 780x. It's what I call a budget system, only cost about $1200 and almost performs as well as my $4000 system with an Intel Q9650 OC'd to 4.1 Ghz with a FSB of 1800 mhz, Asus Striker II Extreme, Corsair Dominator DDR3 1800mhz, XFX GTX 280 XXX times 3, Liqiud cooling on the CPU and NB, Pioneer Blu Ray, WD Raptor. Nice.