Building a System, but need help on the motherboard.

Your budget is in $ so I'm assuming you're in the US. If you're in Canada say so, or you'll get useless newegg links.

Try to get 2x2GB rather than 4x1GB.

Asus P5Q Pro ($150) is a good modern motherboard, for example. Or GA-EP43-DS3L ($100), if you don't need RAID.

Are you sure you want a 9800GTX? The HD 4850 is cheaper (at newegg, at least) and faster in most benchmarks I've seen.

OK, first of all, avoid the mobos with dual DDR2/DDR3. All you really get is a higher price and lower overclocking ability. I've discovered that too late, with my own GA-P35C-DS3R with dual support.

Stick with something with DDR2 only. By the time DDR3 is worth buying you'd need a Nehalem motherboard anyway, you won't be able to reuse any MB you buy today with a Nehalem CPU.

Between HD 4850 and 9800GTX. They trade blows. I'll stick with 1680x1050 comparisons, since those are the 20" or 22" monitors which most people have these days.

http://www.techspot.com/review/103 [...] page4.html
Crysis: 9800GTX wins by 1 fps (33.1 instead of 32)
Devil May Cry 4: HD 4850 wins by 5 fps, but it's irrelevant since monitors can't display 125 fps
Quake Wars: HD 4850 wins by 26 fps, but again it's irrelevant
Supreme Commander: HD 4850 wins 61 fps vs 58 fps, or 54 vs 51 with AA/AF. The monitor can show the difference but you won't notice it.
UT3: the 9800GTX wins by 3 fps, but it's pointless again (131 fps, 128 fps, the monitor won't show that many fps)
World in Conflict: the HD 4850 wins, 34 fps vs 31 fps. You won't notice it, I guess.

I'd say they are identical for all practical purposes. If you want two cards though, you're better of with the ATI card because then you can use a quality motherboard with an Intel chipset and avoid nVidia's SLI chipsets. Also, two ATI cards scale better than two nVidia cards usually, it's a somewhat better mechanism.

Do you like the NZXT Tempest? I'd prefer it to the Lexa because it has better cooling.

Check out www.ncix.com. It often has excellent prices. Also, if you're not in BC, you don't pay the PST (that's 8% in Ontario, for example)
Here's a HD 4850 for $190 or $180:
http://www.ncix.com/products/index [...] re=Diamond
http://www.ncix.com/products/index [...] acture=HIS