The SB will allow a faster selection of processors and newer technology. You can probably sell the i7 on ebay and take some of the sting out of buying a new processor. The rest of your hdwr is reusable, including the cooler; 1156 and 1155 use the same spacing.
oooor you can hold out until this fall and get Ivy Bridge + Z78 = o.O <3<3<3. That might be overkill though. Overclockers are getting I7-3770's to OC to 7+ ghz, can't wait to see z78 chipset with Ivy Bridge.
I am outside the US, so the Gigabyte GA-Z68MA-D2H-B3 was the cheapest Z68 mobo I´d find, but I am not sure if it is a good board. I could get a Gigabyte GA-Z68XP-UD3, or for little more money an Asus P8Z68-V LX, what you´d say?
Gigabyte makes good boards. I put them right up there with Asus (almost). The first Gigabyte board you mentioned is a fine basic Z68 board. If you do a lot of OverClocking, you may want to move up, but the board is fine if it has the features you want. It has solid caps, SATA 3, Gen 3 PCIe...
Stay/Go - depends on what you're doing with the PC. Average Joe stuff then the SB or SB-E will add practically zero to your equation.
If you're rendering then in most cases a 6-core is best (i7-3930K), gaming the difference in cost i.e. the cost of the CPU then IMO keep the X58 and for the money spent add another GPU (or two) and you'll smoke the SB. Equation: Same money (SB + LGA 1155) < (i7-920 + LGA 1366 + 2nd GPU) <or> (SB + LGA 1155) < (i7-920 + LGA 1366 + NEW GPU).
I have also been asking the same question - I've still got an X58 system with 920 overclocked to 3.99GHz. Add to this 12GB, Revodrive X2 SSD 240GB, GTX580, a USB3 SATA 6 card plus a few HDDs....the 'old' X58 is very expandible!
What I've found out is that this system is still very strong....for my needs anyway (gaming, video editing, audio recording) - i.e. you've still got a helluva system here!
Yes, the (very recent top of the range) X58 is "a thing of the past" BUT I have also found out - very conclusively - that Sandy Bridge WILL NOT add significantly to a fully loaded and overclocked X58 system. Do also take into consideration all your software migration and tweaking requirements (mine's pretty extensive) - you don't want to do that for little gain.
I hope you had overclocked that 920 - you will get a significant jump from the 2.6 stock on air alone!
ON THE OTHER HAND, since you are getting a new m'board, and since most of you're components (except cpu + memory?) will transfer an SB system, you'll have to weigh up the additional cost of cpu+memory+complete re-install over getting the (exact) same m'board replacement + old image restoration. Your current/future needs will dictate this. In time, I will upgrade my base (m'board+cpu+memory) but not yet - even Ivy dosen't get me too excited!! Just my 2 cents.
Agree with Mesa. After evaluating everything it was going to take to go from i7920 -> 3770k, I decided to hold out for Haswell. Imo, that would be the next logical time for us i7 gen 1 people to upgrade to the new hottness.