It comes to $1240 without shipping (that also includes some tools and glues).
I was considering switching to the P45. I know the X38 is better but I am unsure if I will want to just up and buy a new video card later to upgrade in a year or if I will CrossFire two of those HD 4870 cards.
Would it be better to downgrade the mother board and perhaps buy 4 x 2GB ram sticks?
I actually don't have a problem with that build at all. It should be fairly easy to upgrade, even if it's not compatible with the CPUs that come out at the end of the year.
I would take a PC of that build any day. Then I could add another GPU, 4GB RAM, and add Vista 64bit/Win 7 as an upgrade halfway through the PC's lifetime.
What I am wondering is if it would be better to do the P45 and save $75, and then in 18 months or so just buy a next gen card for $300 instead of buying a second HD 4870 (which I would guess would probably be down to $200 or so by then?).
In 18 months or so you will probably be looking at a new system, not just a new video card. If thats the case, go cheap, save your money and rebuild in 18 months.
If you want it to last you need to do a couple of things then.
Buy a mobo that supports Xfire without a bottleneck, EI a X48 like the one I listed below. The P45 is a low buck mobo thats basically designed to run a single graphics card at full speed or 2 at crippled speed. The P45 may be all you need though if you never do Xfire and just change your video card as needed. The point here is that the mobo is the controlling factor for your upgrade path. Id go with a X48 so I have as wide an upgrade path as possible.
The OCZ PSU is simply OK for a single card setup. Buy a PC Power and Cooling 750 watt. The OCZ unit may not be enough for Xfire
Buy 1 4870 now, buy another 6 months from now.
The 2 updates I suggested will add a few bucks to you purchase but I think youll be better off in the long run.