My 5100 used to idle at around 33-35*C (yes, cool for a 5100, but I didn't do anything unsual so I don't know why folks' systems go right to 50*C right away)

I always used DVD watching as a good mid-range gaging of temps.  DVD watching was typically 37*C to 43*C.

Gaming would take it to 58*C to 63*C and that was about the top.

I cleaned the heatsink/fan unit one time in one year at about the 8month point and got some dust bunnies out which cooled things down again, but I think everyone's should run like mine did.

It has been suggested that perhaps my sensors were off, but it seemed to climb to a normal high-level so I'm not positive that's the case, but I won't say it's not true.  I just know what the sensors told me.

In comparison/contrast my 600m runs a tad warmer at idle (35*C-39*C) and DVD watching is usually in the mid 40's with gaming at around 53*C to 55*C.  The peaks are cooler, but the low/mid range temps are higher.  In that regard, Centrino wasn't so *kick-tail* as it seemed to be.   Go P4 power!!!!!!!   Har har!!

Overall my 600m is significantly warmer than my 5100 was.  Probably the argument of more-room, but I think my 5100 was quite a cool-running system.  In fact, the only thing I could ever feel get hot was exactly where the graphics card was....(ATI 7500).....under the rear-middle of the laptop.  If I wasn't gaming with it, it was definitely cooler than my 600m runs at now.