All, I recently upgraded from a MBP Core Duo 2GHz (which my girlfriend now enjoys) to a MBP Core 2 Duo Santa Rosa 2,2GHz, 15-inch. The MBP CD always was a lovely quiet machine. Hardly ever would the fan's rev up so you'd hear them. The MBP C2D SR however rev's up when on the power-outlet with a battery that is almost empty (working on battery or on outlet with charged battery is no problem) with simple tasks like scrolling through a 4 gig iPhoto library (exessivey, as in constant scrolling). The rev's of the fans quikely hit 6000 rpm! I compared both machines. Whe working normally, charged battery, on power-outlet, the memory controller of the MBP C2D SR is on average 10 degrees celsius hotter than the MemController of the MBP CD. Than I did a 'yes'-test (type in yes in terminal and hit enter, this will stress the CPU). Let both machines run for about 10 minutes. Here are the temp readings on both machines (in degree celcius)? MPB C2D SR: CPU 69 GPU 69 GPU Heatsink 59 Heatsink A 55 Heatsink B 46 Enclosure Bottom 38 Memory Controller 64 RPM 5479 MPB CD: CPU 70 GPU 51 GPU Heatsink 58 Heatsink A 34 Heatsink B 37 Enclosure Bottom 36 Memory Controller 58 RPM 4890 Especially the heatsink's differ a lot (more than 20 and 10 degrees celcius). What might be the reason for these high temp differences? thermal paste? I hate the machine reving up so much, i am used to the quiet fan's of MBP CD and Powerbook G4. What are the readings other MBP C2D SR owners get? And, do you all have the same issue with revs going quickly to 6000rpm when charging empty battery and doing minor things like scrolling through iPhoto? (i think this also is related to the MemController reaching temperature of 61 degree celcius, this is when the fans kick in big time.