Jann, what xeon system do you have ? I really need to buy few new systems, and I originally wanted 2x2687, but I see many people have some trouble with performance scaling with double socket, at which case, I would just buy few new 4930k, but I would not be so happy about that...
What performance gain do you get in "real scene" ? Thank you much in case of answer :- )
Nakama's result is utterly depressing to see double top xeons perform only as good as single 3930k, while the result should be 2.5x higher. Maybe it is only the benchmark setup, but I would like to see the performance scale decently equal in all situations..
I have dual E5-2660 ES xeons in Z9PE-D8 WS board with 64Gb ram. On A4 benchmark they get 3.59 - about the same as overclocked 2700k@4.2Ghz we tested. In real scenes using A5 the xeons got 2-3 times better results than OC'd 2700k. So I suspect that A4 code just didn't scale as well as A5 does :)
If you're looking at retail xeons, 3930k or 4930k is definitely a better price/performance option. If you feel adventurous to get some ES cpus, then 2687w C0 could be a good investment. Or wait for the new Ivy gen xeon range with 10 and 12 cores and get ES of those :D
If anyone has some top of the line dualsocket machine and some time, please add me on skype, I'd like to do some testing ;)
You can find me on skype by ragsjv :)