Approximate Purchase Date: Next couple weeks Budget Range: $600-$800 System Usage from Most to Least Important: Gaming, surfing the internet Parts Not Required: keyboard, mouse, monitor, speakers, OS - Windows 7 Pro Already Have:
GPU: Sapphire 5870
Case: Antec 902
HD: WD Black 1.5TB
Preferred Website for Parts: newegg.com, have a microcenter about 40 min away. Country of Origin: US Parts Preferences: No preferences Overclocking: Not Likely at the start, would not mind the option later on SLI or Crossfire: Not Likely Monitor Resolution: 1920x1080 Additional Comments: Mainly for RTS and MMORPG games (ie. Starcraft 2, Wow, Diablo 2)
I would like to get the remaining parts in the next week or 2.
Can you wait a little longer? The new Intel CPUs will supposedly be released Jan. 9th, and these will either provide a drastic performance bump at roughly equal prices or a price cut in existing parts. I know the 9th is within that 2 weeks, but I doubt you'll be able to find the new CPUs in stock immediately. I also don't think the price drop on the existing CPUs will be immediate either.
Another question is if you're sure you won't want to Crossfire later. I wouldn't advise adding the second card now, but it'll be a nice cheap upgrade down the road. I'll include a board (and PSU) that supports it, and one that doesn't.
I'll pretend that the new CPUs won't be available to you. Check back once they're released to get a final recommendation.
EDIT: I should point out that with the i5/Crossfire option, you'd have enough cash left over to pick up a second 5870 now. Or you could blow it on a SSD (like OCZ's Vertex 2 120 GB or Agility 2 120 GB or G.Skill's Pheonix Pro 120 GB. You really don't need that much GPU power for what you're doing (even a single 5870 is overkill), so the SSD would probably be a better choice. However, I don't like how expensive they are right now, so I don't typically recommend them.
Crossfire is generally a great upgrade path. Picture getting another 70% performance in several years, and paying almost nothing for it. You'd essentially be buying a single "obsolete" card at that point in time, which will be very cheap. However, given what games you've listed, Crossfire won't really do that much for you. The games you gave as examples aren't very demanding on the GPU or CPU. Spending the extra money on the second GPU won't give you any noticeable performance gain. If you were to start playing the cutting edge FPS games, or playing on an Eyefinity (three monitor) setup, then you'd likely need to the 5870 to keep up.
That XFX is a good deal, since it's the same price. The rebate must be new (as in since I posted) or I just didn't see it. I was comparing the Corsair at $100 to the XFX at $130. You should generally stick to Crosair, XFX, Antec, Silverstone and SeaSonic to ensure a quality PSU. Modular doesn't really matter, as the Antec 902 is a bottom mounted case. The excess cables are already held out of the way at the bottom by gravity. No reason to pay for the same thing twice.
That 5870 is a steal! I just bought a 2nd 5870 myself and I'm blown away at the gains in (most) games. Check out the motherboard I use, the Biostar T5 XE CFX-SLI. It's a great overclocker and its cheaper than ASUS. It is a little on the small side, my 2nd 5870 covers 3 of my SATA ports, which isnt a big deal if you have angled SATA cables. Good luck!