Laptop cooling

[a31pguy]

Ok. Upgraded to a 2.4 Ghz P4-M. Everything is fine and dandy. Running at full speed and intensive HL2 game action the CPU can get up to 80 C. At 77 C the CPU throttles back to try to control the temperature until it cools to 65 C - then throttles up again. The fan runs at variable speeds until it's above 65 C - then at high temps is at full speed. (You can try this when using calc and typing 99999999! and letting it run for a while).


My question - are there any better laptop cooling schemes than external fans? Further is there a way to run the CPU fan at full speed irrespective of the CPU temp? Has anyone found a better fan for the A31P? Liquid cooling? Bigger fan blades? Another laptops Fan/Heatsink?

[daeojkim]

I would like to know about this as well.

Dry ice????

[a31pguy]

Some thoughts

Tom's hardware:

"maximum junction temperature of the mobile Pentium 4-M can be up to 33°C higher than those of a desktop CPU (Desktop P4 Max is 80-95 C). Intel defines the maximum junction temperature as the hottest point on the processor surface, which determines the maximum temperature at which stable operation can be guaranteed. "

Since nano/oil magnetic cooling systems aren't happening anytime soon. And water cooling a portable laptop is impractical. There are only three roads that I can see.

1. Alter the cpu throttle back algorithm since the Pentium 4-M can run to hotter.
2. Alter the stock CPU fan assembly to provide better heat disapation.
3. Use a heat pipe type of laptop cooler.

Really it comes down to 2 or 3 that are practical.

[a31pguy]

found this on sourceforge:

EXPERIMENTAL: fan speed, fan enable/disable -- /proc/acpi/ibm/fan
-----------------------------------------------------------------

This feature is marked EXPERIMENTAL because the implementation
directly accesses hardware registers and may not work as expected. USE
WITH CAUTION! To use this feature, you need to supply the
experimental=1 parameter when loading the module.

This feature attempts to show the current fan speed. The speed is read
directly from the hardware registers of the embedded controller. This
is known to work on later R, T and X series ThinkPads but may show a
bogus value on other models.

The fan may be enabled or disabled with the following commands:

echo enable >/proc/acpi/ibm/fan
echo disable >/proc/acpi/ibm/fan

WARNING WARNING WARNING: do not leave the fan disabled unless you are
monitoring the temperature sensor readings and you are ready to enable
it if necessary to avoid overheating.

The fan only runs if it's enabled *and* the various temperature
sensors which control it read high enough. On the X40, this seems to
depend on the CPU and HDD temperatures. Specifically, the fan is
turned on when either the CPU temperature climbs to 56 degrees or the
HDD temperature climbs to 46 degrees. The fan is turned off when the
CPU temperature drops to 49 degrees and the HDD temperature drops to
41 degrees. These thresholds cannot currently be controlled.

which seems to point to the embedded controller having a hand in turning on the fan for not only the CPU temperature - but for the HDD temperature as well.

[a31pguy]

One thought that came to mind was converting an Ultrabay HDD Sled into a UltraBay fan that ports out the side of the case. But on closer inspection, why waste an Ultrabay HDD sled. Why not use the Ultrabay spacer that came with the laptop. It's got to be good for something. A quick trip to Fry's Electronics and I returned with a dual fan hard drive cooler. A 44-pin IDE connector (DC power pins are at 44 and 41) and some soldering would power the two 40mm fans encased in a small electric blue anodized aluminum frame (which is encased in the sled) I'ts a VANTEC HDD Cooler (part HDC-502A). Some venting it the exterior of the ultrabay spacer. I will be looking for a low profile fan shield to direct the airflow to interior of the case. The fans will act as a blower and the CPU fans will be the exhaust. Mounted on the left side of the case this should give the a31p a cooler interior and also increase the GPU cooling.

After looking into the A31p case at the ATi chip - I elected to use aluminum finned memory chip coolers because they are small, low profile, and come with thermal adhesive compound. It's better than nothing at all.

By default the Ultrabay has some airflow to the main case - so installing the dual fans or a small blower should help keep the interior of the case cool when under load. Using the ultrabay spacer allows for me to reuse a part that would sit on the shelf without modifying the case of the laptop.

Presto - a new IBM accessory. The Ultrabay 2000 Fan Array. I'm planning to build another for the other Ultrabay slot.


Initial results are good with the hdd temp at 35-38 C and the CPU cooling down very rapidly after long heavy usage.