I thought I'd share this with you, and pose a question too:
This is about how I made my laptop run quieter, cooler and use less electricity.
Whilst investigating why my laptop fan ran almost all of the time, I eventually discovered that it does have an alternative power mode where it runs at a reduced voltage and so produces less heat and requires less fan-cooling. In adopting this method, my own laptop, previously with fan running 80%+ of the time, now hardly ever has the fan coming on at all, and it stays much, much cooler; I don't notice any change in its performance speed - with my typical load of <10% CPU load - and the operating frequency of the CPU remains at 1.5GHz.
The method that achieves this for my HP Compaq Presario V4215EA is:
1. Do not have mains power to the laptop when I turn it on; either disconnect the mains lead, or better, turn off the mains power switch at the wall.
2. Switch on the laptop under battery power; once the laptop has started running and a logon screen appears, I can, if I wish, turn on/connect the mains supply. It is the power-up-under-battery that is the key; removing mains supply whilst running does not have the same effect, and the effect is independent of what o/s is used.
Maybe this method will work for your laptop too.
In this reduced-power mode, the laptop heatsink naturally dissipates heat from the CPU and reaches a steady state of around 44C at <10% CPU load. If I don't follow this method, and use mains from the start, the CPU temp rises rapidly and once (approx) 57C is reached, the fan comes on and attempts to cool the CPU to below 40C, that is rapid on a cool day - on a hot day it can struggle to make the final cooling step from 41/42C to 39C. The temperature then see-saws in that 57C<>39C range with the fan being on 80% of the time.
There are no settings in its (latest) BIOS to do with power/heat/fan etc.
Question: Since I don't see a drop in CPU frequency, or notice a drop in speed performance (at my <10% load), what, if any, is the drawback in adopting this mode?
As part of the investigation, I experimented with the CPU<>heatsink interface; BTW the fan is clean and in good order and so is the heatsink.
Over a 10-day period I tried different combinations of cleaners, thermal pastes and shims - briefly summarised below - all tested under same load conditions (in the low-power mode described above):
With thermally-pasted 0.6mm copper shim in place - settles at 46C
With thermally-pasted thinner aluminium shim - 46/47C
With thermally-pasted thinner 99.9% pure silver shim - 43C
With no shim with minimal paste - 45/46C
With no shim and no paste whatsoever - very erratic - lowest temp 39C, but more/higher spikes - unable to get a 'settled' state....fluctuates 39/55 all the time
I used 3 different kinds of paste, cheap>expensive; I detected no difference in their performance.
I found that very, very minimal paste application worked best, and rubbed it in with a credit card edge.
Hope you find this informative.