I am planning to upgrade and I am not sure whether I should go with 1156 or 1366.
1156 is rather new and will stay for some time but what does the future hold for 1366?
Since it's also a server socket it probably won't die any time soon but will it stay within high-end consumer's range?
LGA1366 - has the better high end performance due to the extra memory channel. As for the next 2-3 years LGA1366 should be a round for the foreseable future.
It has a long future, first off you were correct, the Xeon W55xx processors use the 1366 platform and intels new consumer grade hexacored processors (core i9) will be released for this platform.
I say 1156. We don't know which mobo platform is going to be mainstream.
And even with the new 6 core / 12 thread cpu (code name gulftown), this will likely be expensive and nobody will be able to afford it. Besides, will existing current RAM be able to support if if you've initially bought the i7 920?
The i7 860 (1156) beats the i7 920 in virtually all tests. Why pay extra for triple channel memory when it's not necessary?
^Uhm...*cough* show me some links please to those tests and show me the specs of both systems. How do you know if its not the RAM, motherboard, or something else that affects the tests?...two different platforms so many other variables come to play besides just the CPU. Moreover, the 1366 socket supports 16x/16x on its PCI-E lanes and the 1156 does not, its only has 16x/8x or 4x. Plus triple channel can actually have some benefits. And don't forget the i7 860 comes clocked at 2.8Ghz and 920 is at 2.66ghz...they are two different processors. Overclock the i7 to 2.8 and see what it does or buy an i7 940 which is around 2.9ghz. Look outside the box, there are many other things at play.