Sorry if this is the wrong place to be asking, I don't know where else to go.
Approximate Purchase Date: Within a month
Budget Range: Less then $500 after rebates
System Usage from Most to Least Important: Battlefield 3 and other games.
Parts Not Required: Keyboard, Mouse, Monitor, Speakers, Win7, Case, PSU Corsair 1000w, Graphics card, CD/DVD Drives.
Parts Required: Motherboard, CPU, Ram
Preferred Website(s) for Parts: newegg.com, amazon.com
Country of Origin: US
Parts Preferences: by brand or type: Quad Core CPU
SLI or Crossfire: yes, in the future.
Monitor Resolution: 2048x1152
Additional Comments: Right now I have a dual core CPU and it runs at 100% on BF3, I would like to get a quad core. Right now my board is a LAG 775, but I think it would be better to upgrade the mb/cpu/ram instead of just getting a Core 2 Quad.
Yes, due to other performance gains from the architecture and memory controller you will get much more improvement upgrading to sandy bridge.
Not to mention that any Core 2 Quads worth while would cost you about as much as a CPU+Mobo with sandy bridge.
I just bought an i5-2500k, z68ma-d2h-b3, corsair vengeance 8 gb today. it's running windows 7 64 bit with no video card and stock fan at 1080p with temps 34-40 C. i haven't tried playing a game on the intel graphics yet but i'm running prime95 with the stock fan while writing this, the temps are in the 70s. using price match with microcenter, it was $375 after tax and i have $25 in rebates to mail in.