So I was looking at the cooling of the 65W G5 as I am trying to see if improvements were possible. I noticed that removing the top case drops the idle CPU temperature by 10C (from ~40C to 30C) so airflow can definitely use some improvements. Increasing the idle fan from 30% to 50% with the case on only drops the idle temperature by 5C to 35C. I researched the fan and noticed that the G3 G4 and G5 all share the same fan design in spite of many different part numbers. There are however 3 models of fans:
The more recent ones are made by AVC and have a current rating on 0.8 Amp.
Some of the G3 apparently had a delta made one with a current rating of 1.1 Amp.
More recent models seem to be using an FCN branded one. The information is engraved and not on a label. Mine only has a 0.5Amp rating but I am seeing pictures of older models with a 0.7Amp rating as well.
I am sensing a cost reduction move on the part of HP here since delta tends to be higher end for fans so I just ordered a delta one.
The delta P/N is BUC0712HB00 1.1Amp
The AVC version P/N is BAZA0813R2U 0.8Amp
The FCN come in 0.5Amp and 0.7Amp ratings
They are not distinguishable from the HP P/N (914266-001 and L19561-001) but are physically a little different.


