Hi

I recently received my new Dell 640m with Core 2 Duo processor -
lovely! Except I got an annoying high pitch noise - barely detectable,
but annoying people with good hearing!

So, looking on the forums, it seems people are reporting the same
problem on various machines, and it seems to be related to the CPU and
the frequency it runs at setting up some sort of resonance.

The advice was to download RM CPU Clock utility (freeware, and very
good!) and disable the "Enable Popup Mode" tickbox in the "Advanced CPU
Settings" section.

http://forum.tabletpcreview.com/showthread.php?t=3516

I have tried this, and it really works! I can clearly detect the noise
stopping/starting as I toggle this setting.

I cannot immediately detect and down sides to this change of setting -
the RM Clock readme states:

"Enable Popup mode (auto C3/C4 to C2) - when this option is off, any
bus master traffic causes the chipset to return from C3 or C4 state
into C0 (working) state. When this option is on and the chipset
observes a bus master request, it will take the system from C3 or C4
state into C2 state and enable bus masters. This will let snoops and
memory access occur. This setting is available only for ICH6-M and
ICH7-M."

I would really appreciate if anyone translate this into real-world
performance/heat/battery life information for me :)

Hope this helps people,
Mark.