I can't seem to find any anecdotal information on Haswell laptop temperatures. My laptop, a few month old MSI GE40, reaches 98-99oC when playing Just Cause 2 with everything maxed after about half an hour. This is when it is sitting on my lap.
It idles around 40oC.
The jMax is 100oC so I'm a slight bit worried, but at the same time Haswell has well-known heat issues and the laptop is tiny. Is this something to worry about, or is this normal?
The AnandTech MSI GE40 review mentions the same thing: CPU temps at 98C. This was right at the edge of throttling, but none was detected (read the comments). So perhaps the designed thermal performance allows the chip to run "full speed" exactly within limits. But that's when it's brand new and doesn't have dust clogging up the works.
When cooling degrades the chip will start throttling down when it hits the max. And it's running at the max for sustained periods just playing a game. So depending on how conservative you think the specification/engineering is, and dumb luck for the particular chip you got, that's somewhere between OK and not a good idea for the long term.
To answer your question, I would say both normal and something to worry about.
You're blocking the laptop's air vents by playing a computer game with the laptop sitting on your lap. If you set the laptop properly on a hard surface, it would let the air circulate properly around your laptop and your laptop's temperatures would go down.
