I had no desire to void the warranty, so I decided to insert a piece of thin, yet difficult to flex cardboard in the middle of the fan vent to stop the fan from being able to rotate. The cardboard was added while the eeePC was in standby.
After resuming from standby I heard a not-so-quiet 'clicking/clunk' sound every 5 seconds coming from the fan. Since the blades of the fan were not able to move, this sound was definitely from the motor's ball bearings which I now know is clearly responsible for the 'buzz/grind' noise we would hear when the fan is spinning (in a room with low ambient noise).
My first objective was to max out the CPU usage for roughly an hour, and observe the increase in CPU temperature. This was accomplished by doing the following (somewhat overkill):
- Three browser windows each displaying a flash based TV show from adultswim.com
- Console window running the 'updatedb' command two times
- Console window running the 'top' command to monitor CPU usage (set to update every second)
- Console window running a script that outputs '/proc/acpi/thermal_zone/TZ00/temperature' (CPU temperature) every second
The Meaningful Data
- The highest CPU temperature reached without any active cooling was only 66 degrees Celsius, which is no where near the 90-100 Celsius critical 'CPU power down' temperature.
- This temperature was reached within 15 minutes of maxing the CPU and did not increase at any point during the 1 hour max CPU usage test period.
- The top and bottom of the case were both warm, but nowhere near 'hot'. I was able to comfortably rest the device on the bare skin of my upper thigh for a short portion of the test.
Idle CPU Temperature 30 mintues after The Test:
- The CPU temperature hovered between 54 and 55 degrees Celsius.
- The case was mildly warm.
What does this all mean?
Irregardless of CPU load, active cooling on an eeePC running at stock speed is unnecessary
Pros of Fan Removal
- In places with low ambient noise you won't have to deal with the buzzy sounding fan noise caused by the bearings in the fan motor.
- Without the fan, you lower the eeePCs power consumption by roughly 1W.
As noted in one of my earlier posts once the fan is on, the fan is incapable of cooling the system down low enough to reach the fan 'off' temperature trip point, because of this the fan never turns off.
Cons of Fan Removal
In order to open the case and disconnect the fan you will void your warranty by damaging the warranty sticker.
After having completed this test, I REALLY, REALLY want to disconnect the eeePC's fan, but I won't be doing so until I find out that someone who has opened their eeePC has successfully received Asus warranty repair service for some kind of defect/issue.
I have removed the cpu_freq and p4_clockmod modules from my system as I deem them to be unnecessary. My doing so should have had no impact on the observed CPU temperatures.
The battery monitoring application 'powermonitor' appears to use 15%-25% CPU usage every 10 seconds while it checks the battery status. I plan to remove this app from '/usr/bin/startsimple.sh' and see if the eeePC battery life noticeably increases.
Edited by NoeeePC4MeWellMaybe..., 27 November 2007 - 09:11 PM.