So I got my new laptop today:
Dell XPS 15 - 9530
Display: 15.6" QHD (3200x1800) Touchscreen
CPU: Intel i7-4702HQ 2.2-3.2Ghz
Graphics: NVIDIA GT 750M + Intel HD 4600
SSD: Samsung SSD SM841 mSATA 512GB
and when I first tried QL I easily got constant 250fps on overkill & campgrounds. I then installed some apps, removed some junk software and played around a little with that laptop until I finally decided to connect my external screen via HDMI (no displayport cable at home :( no 144Hz for me right now). Turns out -> I can't even get 125fps constant anymore.
I fully disabled the Intel HD 4600 graphics and "r_lastvalidrenderer" shows the GT 750M. But for some reason I lag like hell. From time to time I managed to get constant 250 fps in window mode (same resolution as full screen mode). But also that is gone now.
My previous laptop could handle 250 fps easily as well:
MALIBAL Satori P170HM
Display: 17.3" FullHD 120Hz 3D Matte
CPU: Intel i7-2760QM 2.4-3.5Ghz
RAM: 8GB - upgraded myself to 16GB
Graphics: NVIDIA GTX 560 1.5GB
Optical: Blu-ray reader
SSD: Intel 510 SSD 120GB
HDD: Samsung SpinPoint MP4 7200 rpm 640GB
Cooling: IC Diamond CPU + GPU
I am sure my new laptop should also be able to do so. Any ideas what could cause the problems? I believe its some NVIDIA Optimus crap but I already set "USE NVIDIA GPU" in Nvidia control panel settings.