I7 2600k @ 5Ghz or 3930k@ ~4.5Ghz

[Wam7]

I'm currently running a 2600K at 5.0 Ghz with 1.41v. I can pick up a 3930k with motherboard (Gigabyte G1 Assassin 2) for a *very* good price but I'm pondering whether as to how much benefit I will see.
My computer use is varied but I do a lot of encoding to Mpeg4-ASP (Xvid) and Mpeg4-AVC (x264) also a bit of photo editing and gaming as well as music production. Will probably also run some VM's..

Has anybody done something similar or that can give me anecdotal advice?

[glitch]

If your software can use the extra 4 threads from 3930k you will see an improvement, not very much but it will be there. In gaming you'll see no noticeable difference.

[NitrousX]

Seeing your running your i7 2600k at 5.0Ghz and your rendering videos and encoding the better cheaper would be to buy some more Ram get 16GB kit.
But what applications are you using to encode and render?

[DanceswithUnix]

Looks like you are only going to get guesses from people who haven't made the switch.

One thing to consider, that is a quad channel memory system isn't it? In which case, unless you already have 4 DIMMS you will have to factor in another pair of memory sticks else there kind of isn't any point. Bonkers memory interface is what that platform does

Anand bench can compare 2500k with 3930k, not quite what you want but close enough I think.

http://www.anandtech.com/bench/Product/288?vs=552

The h264 second pass, the slow one that matters, performance is doubled. Divx isn't quite as good, but still improved.