Hold on, do we know it is the kernel? It could be something in mesa as well. I am running linux-3.13 git with mesa 9.2.1 from kubuntu saucy, and this has no significant regressions in my testing. Michael mentioned he'll investigate, let's see how it goes.
Originally Posted by tomtomme
Regardless, I've been saying this for months now. Ever since mesa 9.2 + kernel 3.10, where haswell improved tremendously, nothing much happened for haswell, at least in my testing with qgears2, glmark2 and unigine. In fact, many times, kernels newer than 3.10 gave me regressions, though not as bad as this. so i've been mostly running the default kubuntu saucy stack.
Worth mentioning, too, is the fact that both xorg-edgers and oibaf on top of saucy have been really really unstable, to the point that i try every now and then, just to revert to the default saucy stack.
~$ cat /proc/cpuinfo |grep model
model : 60
model name : Intel(R) Core(TM) i5-4670K CPU @ 3.40GHz