Huge lag on my laptop, unless I'm plugged into a tv.

[PwnedDuck]

My stats are: Windows 7 Intel i5 2410M (2.3 GHz) 3072MB RAM Nvidia GT550M with Optimus. Latest drivers.

I can play KSP an indeed most games that I load up for five/ten minutes absolutely fine. Then, almost inevitably, incredibly loud crackling noises start, framerate drops to single digits (and for more intense games to less than one per second) and time ingame passes in slow motion.

Unless I'm plugged into my TV; I have a big tv in the living room which I use as my laptop screen via HDMI cable, and despite being higher resolution than my laptop performance is just fine (none of the above issues at any rate) indefinitely.

I faintly recall that this was not always the case.

I suspect the Optimus may have something to do with this as, again a couple of years ago there were some games failing to distinguish between it and the integrated processor.

I can't just always have my laptop plugged in since I travel a lot and am home only on weekends usually.