I’ve run some tests to measure the PSU temperature in several different scenarios, both with original GD-ROM drive and GDEMU installed. The most interesting case was one with GD-ROM drive but no disc, and cover completly removed:
Without any forced airflow the convection alone is not able to cool the radiators below some 70°C. It doesn’t get any worse than this though, basically the PSU reaches thermal balance at this point and stays that way.
With the cover installed PSU will heat up to about 58°C. Running the console without cover and then reinstalling it after some time will cause the temperature to drop eventually. In other words, the airflow inside the case does make some difference.
I’m a big fan of simple solutions so this is what I did:
I’ve also complety taped off the air inlet at the back of the console, so now most of the airflow will go through these holes and cool PSU down. With GDEMU installed it reached 63°C after an hour. It’s just 5 degrees more than with the original drive so I think I’m done making holes🙂
One other point of interest, PSU voltages:
- GD-ROM drive (no disc): 3.296V / 5.030V / 13.28V
- GDEMU: 3.305V / 5.042V / 14.26V
Even without a disc inserted the original drive pulls some current from 12V line. GDEMU doesn’t (and uses much less power in general) so it’s possible the PSU is running in a bit less efficient way now.
Keep in mind this a 230V PSU, the 110V one might behave differently. I’m going to test that as well in a day or two. Still, the capacitors in the PSU are 105°C rated so 70 rather than 58 degrees is not going to suddenly damage them. If this thing was properly designed it should handle even less favourable conditions than that. After all SEGA guys did put the fan on the opposite side so overheating the PSU was not a major concern for them.