Hello... your Gigabyte motherboard will handle the Q9650 and the 1600 FSB Extreme models... you might consider getting a Q9450 or Q9550 and turning up the FSB to run them at 3.0 to 3.4 GHz easy... save some bucks... and getting the advantage of the 12 meg of L2 cache.
This website shows a performance graph of old and current CPU's... Looks like you could get about a 50% increase of CPU performance at 3.0 GHz.
http://www.cpubenchmark.net/common_cpus.html 3 of the 10 top performers are socket 775 processors... only 1 out of 10 is an i5...
I'm running my Q9550 at 3.0 GHz 24/7 on my Gigabyte P35 board and getting a Windows 7 Experence CPU Index of 7.3 out of 7.9... and a memory index of 7.3 out of 7.9... A bios upgrade is a very easy thing to do if needed...
This is the Gigabyte Website for your current Motherboard...
http://gigabyte.com/products/product-page.aspx?pid=3137#ov Click on the CPU support box and you will see the Bios versions are the same for the Q6600...
I picked up my retail BOX'd Q9550 at Micro Center, a few months ago for $169.99... but I see they are out of stock now... retail now looks like $265.00... but looks like good ol' Ebay has plenty of auctions for them.
Looks like you could get about 85% increase of CPU performance with the i7 860... Micro Center price $229.99 for the i7 870.
Looks like you could get about 96% increase in CPU performance with the i7 930... Micro Center price $199.99 for the i7 930.
Looks like you could get about 20% increase in CPU performance with the Q8300-Q9300... Micro Center price $119.99-$139.99 for the Q8300-Q9300
Always a balance of price and performance choices as prices change week to week and month to month...
post edited by IronSound - 2010/09/16 17:57:57