latency-histogram gets error messages

Here is a list of things to disable in the bios:
-hyperthreading < really bad for latency
-serial ports <do not know how bad but i disable always
-infrared if any< does mess up latency
-modem <all are software using the audio card, all bad for latency
-speed step < with RTAI it has to be disabled, with RT-preempt not obligatory
-APM <things like suspend HDD and some others, not totaly disabled
-cpu throtling < usually no difference, but if it heats up it will slow down everything
-web cam if any < usually through USB so not obligatory
-virtualizations < all, there are several on new hardware
-procesor power states <some laptops have that too

I had several cases on laptops that did terrible latency with those active and got to quite usable after disabling those, i am on a Lenovo T420s right now getting 34100 on base and 20900 on servo thread with RT-preempt and 8 glxgears running while browsing the forum, before disabling everything i do not need it was over 4000000 on both. New DELL laptops do badly on latency, but still under 300000 on base thread.
Almost forgot,
New high end laptops (like the before mentioned Lenovo T420s) have 2 graphic cards and they can switch between them on the fly (while working), one Intel and one NVIDIA so there is a BIOS setting for choosing one of them or both, i choose INTEL and disable switching.