MB/CPU/RAM upgrade for gaming

[RevMen]

1) What will you be doing with this PC? Gaming? Photoshop? Web browsing? etc
Games (especially BFBC2), Sonar, Reason

2) What's your budget? Are tax and shipping included?
<$1000

3) Where do you live?
Austin, TX, no Microcenter that I know of

4) What exact parts do you need for that budget? CPU, RAM, case, etc.
CPU, which will lead to Motherboard and Processor

5) If reusing any parts, what parts will you be reusing? Please be especially specific about the power supply. List make and model.
2x XFX 5850 Black Edition
XFX Black Edition PSU (no worries here)
Silverstone Fortress FT02 case
MOTU 828 mkII (need good firewire)

6) Will you be overclocking?
Willing, but don't necessarily need to.

7) What size monitor do you have and/or plan to have?
3x 1600x1200 monitors eyefinity

8) When do you plan on building/buying the PC?
Soonish, but can be convinced to wait if there's a good reason

9) What features do you need in a motherboard? RAID? Firewire? Crossfire or SLI support?
CrossFireX
Need 2 RAID1 Arrays at least.
Good firewire for MOTU

10) Do you already have a legit and reusable/transferable OS key/license? If yes, what OS? 32bit or 64bit?
Windows 7 Ultimate 64

I currently have a QX9650 on a Gigabye EP45-UD3P with DDR2 1066 G.SKILL 2x2GB. I've got the processor stable at 3.8 GHz, but that's the best it can do. I'm sad that I can't get it up to 4 GHz. Maybe a better cooler is the answer. Currently have Arctic Cooling Freezer 7 Pro Rev2.

Even if I could get it up and over 4 GHz, though, I don't think I'd see a huge improvement in BC2. There is a very noticeable improvement between 3 GHz and 3.8 GHz, though.

I'm thinking i7 is the answer. I just don't know if it's worth paying for it now. Looking for input on 1156 vs 1366, Intel vs AMD, Good vs. Evil. I already get very good frame rates, but it's still just a bit choppy when things really heat up. I just want silky smoothness all the time. Is that so much to ask?

 

[Dangman]

In this particular case, you might not see a good performance increase from a Core i5 or Core i7 setup.

 

[RevMen]

This article doesn't agree:

http://hardocp.com/article/2009/05/19/real_world_gameplay_cpu_scaling/

What you guys really want to know, "Is the Core i7 CPU really faster in games than the Core 2 Quad?" Based on this evaluation at both default and overclocked frequencies we can make that determination. The Core i7 is faster than Core 2 Quad in most real world gaming scenarios. Playing Crysis Warhead resulted in the 2.66GHz Core i7 920 providing the SAME level of performance as the faster clocked 3GHz QX9650. We know for a fact this game is CPU frequency intensive, yet the lower clocked Core i7 was pulling in the same performance as the higher clocked QX9650. When we overclocked both CPUs, yet again, the Core i7 was faster than the slightly higher clocked QX9650. In Fallout 3 the Core i7 was actually a lot faster than the QX9650 when both were overclocked.

 

[Dangman]

I should clarify: "A good enough performance increase to justify the price." If you look at the performance increases, it's usually only single digit FPS increases for a majority of the games in that review. Maybe a few double digit FPS increases for a handful of them.