I really want to know and am surprised that no one has posted heat comparisons tween the macbooks etc old and new.
In fact is there a heat difference in CPU's tween the higher and lower models?
The 2.53 unit may be an overclocked cpu hence more heat,
can anyone put me onthe right directions to get the info?
"Overclocked" isn't really the right term. It's a different part, and would've been higher-binned. 2.53Ghz is it's stock setting. That said, it probably does run a bit hotter, that's just the way these things work.
Some average temps from my own machine (never spent any real time with the new MB or the old MBP, so can't offer anything up there)
Idle, 9400M
CPU 40-45C (a little cooler if it's on a table in a cool room)
GPU 40-45C
Northbridge 38C
Enclosure Base 26C*
Idle 9600M GT
CPU ~50C
GPU Diode** ~57C
Northbridge ~50C
Minor Load (iTunes encoding), 9400M
CPU 58C
GPU 50C
Northbridge ~48C
Heavy Load(Cinebench Multi-CPU render), 9400M
CPU 70C
GPU 50C
Northbridge 55C
Heavy Load (Cinebench Multi-CPU render), 9600M GT
CPU - 80C
GPU Diode - 77C
Northbridge - 68C
*There are 3 sensors labled "Enclosure Base", all of which read within 1 degree of each other all the time, usually showing a temp around ~25-30C. Interestingly, they don't change much, even during the "Burn-in" Cinebench test with the 9600M GT. This leads me to believe they aren't actually reading the base, but more likely the underside of hte Logic board, as kind of an "Ambient temp" sensor, reading the temp of the air the cooler is "breathing in"
**There are 2 GPU core sensors. One, labeled "GPU" appears all the time, and I think it is the on-die sensor from the 9400M. The other, labeled "GPU Diode" only appears when the 9600M GT is switched on, and is apparently its on-die sensor. It seems the 9400M cannot be disabled due to being part of the Northbridge.
One last note: During all of this, the fans stayed at 2000RPM. A little shocking at first, but remember the max temp for these chips is over 100C, and the machine was not uncomfortable hot on the bottom, meaning there is little reason to slash battery life and silence by ramping up the fans, so I think this may be intentional, although if anyone else has gotten their fans to ramp automatically, I'd love to know what the temp was and what you were doing at the time. Also, repeating the final test (Cinebench w/9600) with the fans manually set to 3800rpm (~60%) drops temps across the board by about 10C. Haven't tried it with the fans at full.