2 CPU, identical performance, TDP 35W and 28W

How much temperature drop could I expect from replacing a CPU which has a TDP of 35 W with another one which has a TDP of 28 W? Both CPU have identical performance.

http://ark.intel.com/compare/42599,35563

Currently, the one I have with 35 W TDP would go from 58 to 81 Celcius.

 

Theoretically, the lower power cpu will run cooler, but 7W is not a huge difference. TDP is also derived as an average value. Actual power draw from the cpu can go higher than the TDP rating. The lower power one may give you a couple of minutes of more battery runtime though.

The biggest factor in temps is how good your laptop's cooling system is designed. Thermal paste can also play a role but not as much as the actual capability of the heatsink to transfer and expel heat away from your processor. If you are concerned about your temps, you can try cleaning the fans and replacing the heatsink compound. Another major factor is ambient room temperature. You can also look into getting a notebook cooler; they sometimes help, but I would personally not replace the p9600 with the p9700 (unless you can get one for free )

 

First try undervolting the T9600. Most likely you can get the voltage down significantly. At the start of the production of those chips the P chips were definitely selected after testing but as the fabrication process improved many of the T chips would have passed the lower voltage test but the main market was for the cheaper T chips.

John

 

@hendra you would get more performance as well as slightly less heat by getting a T9900 instead. If your T9600 doesn't climb over 90C under Prime95, there's no point in P9700. And I second the undervolting suggestion.

 

Agreed.. My T9400 ran much cooler when undervolted and performed just as well....

 

Depends on the stepping of T9600.
Some T9600 cpu's with a C0 stepping (I think) ran way more hotter than their E0 equivalents... still, it is also a combination of factors (cpu stepping, plus chassis, etc.).
I agree you should try undervolting T9600 first - it will probably produce similar, if not better results for you (especially if you combine it with a good thermal paste).

I remember I used T9600 and it ran pretty hot when under load.
I replaced it with P9600 and this thing runs pretty cool on it's own... especially undervolted (but my laptop has pretty poor cooling).

 

Try to under volt with a program called rmclock. I use that to under volt a t7300 and t8300 many years ago.

 

RMClock is buggy. I strongly suggest CPUgenie instead.