September 22, 2019

Redneck Notebook Cooling

Background

We had some problems with a water leak here in the apartment. So the builders fixed us up with a device that helps to dry the walls. This device works basically like a strong vacuum cleaner. It sucks the moist air from the brickwork of the wall and transports it to the outside of the apartment with a long hose that hangs out of the window. The "Vakuumtrocknungs System" looks like this:

Idea

The other day I was procrastinating and felt like using the vacuum device to build a strong laptop cooler. So I took the hose from the window and measured its diameter. Then I created an adapter from an old shoe box. The one side of the adapter fitted the hose, the other side was an open square that I duct taped to the bottom of my notebook. The intakes of the notebooks (yet limited) cooling system are also located on the bottom of the notebook. This way I sealed the outlet hose of the wall-drying-system to the intake of the notebooks cooling system. Here is a picture:

I turned on a CPU temperature monitoring program, started cinebench and then switched on the air-drying-device. The CPU and GPU temperature droped immediately from 65° to about 38°. Very effective! According to the specs this air-drying-device moves about 80 m³/h at 200 mbar :D Actually the pressure from the device was so strong that I had to reenforce the duct tape with a second layer. A lot of air goes through with this redneck cooling. The next step was measuring the performance gains.

Results

Running with the default cooling resulted in 812 point in cinebench. Here are the temperature curves of running cinebench with the stock cooling:

With the redneck cooling the cinebench score was 829 point, which is well within the margin of error of the previous result. Here are the temperatures with the redneck cooling:

Conclusion

Is was a fun way of wasting time, but this redneck cooling does not help with performance. Now I would really like to know why this does not work. The temperature drop is significant, and this should allow the CPU and GPU to turbo for a longer time. My only explaination is that the CPU and GPU maximum turbo length is set in by the manufacturer. Unfortunatly I cannot conduct any more tests, since the walls in the apartement are fixed and dry again, and the builders have taken back the oversized laptop cooler air-drying-device.