I have not been able to find much information about Qlikviews utilization of Intels Hyperthreading, but from what i could find, it seems it should be turned off. Have you guys tested this or got some documentation on it?
"Hyperthreading is designed to help deal with unoptimized applications and the limitations of operating system schedulers. My understanding from the last time that hyperthreading was actively marketed is that QlikView does not benefit and can actually suffer when hyperthreading is enabled. QlikView has highly optimized code and uses it's own threading algorithms to maintain peak performance. Hopefully someone from QlikTech can confirm in the comments that hyperthreading is not advisable."
I have run into the same problem before and the solution is to turn-off hyper-threading. Also, I have found the six-core processors perform better than eight-core's for some reason. Although, I haven't tested any application in the new e7 family, sounds interesting.