I am thinking about upgrading my system to a i7-975 with 12 to 16 gb memory. I do not plan to overclock at all. My current system is a E8600 with 8gb memory (maxed out on board). I do alittle video editing, watch tv through tuner card, and play wow (alot of times having 2 accounts open on different monitors). Will I see any difference with this upgrade? My other option is getting a new board to support my current processor and adding more memory. Either way I would have to buy more memory. If I stayed with DDR2 I could use some of my existing memory and finish the upgrade to 16gb at a later point, but how would this be as far as performance compared to going with DDR3? Any suggestions would be appreciated.
You would most definitely see a massive performance increase by upgrading to the i7. Since the E8600 uses the LGA775 socket (which is all but deceased) and the i7 uses the LGA1366 socket, you would definitely need a motherboard upgrade. And if you're talking motherboard upgrade you should be thinking seriously about using DDR3 instead of DDR2. It provides a much better upgrade path for the future and DDR2 won't be around for much longer either. 16GB of RAM does seem a bit overkill though to be honest. If all you do is a little video editing, watch TV and play WOW then I can't imagine why you would need that much memory. Do you use the full 8GB you have at the moment? Hope this helps!
Yeah I would say Asus or Gigabyte are about the best around at the moment. Have a look at some on Newegg depending on how much you wanna spend and read up on some technical reviews before you make your choice. Sorry I can't help more; I'm not too hot on i7 mobos!
If you go 16GB you'll only be running in dual-channel memory, so stick with 12GB to keep triple-channel. Yeah granted only synthetic benchmarks show the difference, but if you're investing this much money in a system you might as well optimise it fully.
Now I know you're not interested in overclocking, but it's easy to do and I personally would suggest you're wasting your money on the 975 if you only do a little video and play WoW.
Go for the i7 920 (or 930), give it a mild overclock to reach 3.33GHz like the 975 and spend the $600 you'd save on something more worthwhile, like a SSD for your boot drive or a ***-hot GPU like the Radeon 5870.
Also, X58 motherboards are DDR3 only so you won't be able to reuse your RAM anyway.