HP Z4 G4 front fan is under utilized causing poor GPU ventilation

[Salour]

I have a HP Z4 G4 with a NVIDIA GPU, when GPU is working it gets very hot and air in lower section under GPU becomes hot and further prevents GPU cooling, but system ambient temperature remains relatively low and front fan doesn't speed up to clear hot air.

I could increase the Idle fan speed as a temporary workaround but I wish to learn how to properly adjust the fan speed so it increases only when GPU is producing heat.

HP documentation seems incomplete and inconsistent and raises more questions, I appreciate if you can give me some instructions and also please answer following question as much as you can

1- in the bios, there is option for PCIE Idle fan speed increase, is PCIE fan the same as front fan or something different?

2- in bottom left section of the mainboard there is AUX fan, what's the use of that fan and how that gets controlled, I couldn't find any documentation for the AUX fan, could you please post a link

3- Bios has an option for PCIe Idle Fan Tracking mode, I didn't find enough and consistent explanation of what this option does, could you please explain

4- is there any documentation out there dedicated to HP z4 g4 motherboard and perhaps has more information in it?
5- where the ambient sensor is located on the board?

6- is there any extensions to add temperature probs to the systems and use it for controlling fan?

7- and finally, is there any application that can help me manage the ventilation of this system and be able to control front fan speed?

Thanks in advance for your help

[Salour]

AS nobody answered my question, I write down my own finding as it may help someone else

There seems to be a design flaw in HP Z4 G4:

HP Z4 G4 has a small space and CPU and memory heat flushes out of the space very fast but when someone uses a large GPU, it effectively creates a separate isolated space with higher temperature at bottom of the case which doesn't reflect in temperatures so doesn't increase fan speeds. for example I measured the temperature around 50 degrees while System Ambient Temp (use HP Performance Advisor to read it) shows 20 Degrees C.

I really like someone from HP, prove me wrong or shows some workaround to this issue

Answer to my other questions:

1- in the bios, there is option for PCIE Idle fan speed, that basically is the combination of front and rear fan

2- in bottom left section of the mainboard there is AUX fan, there is absolutely zero documentation for that fan, and I couldn't make it run faster.

3- Bios has an option for PCIe Idle Fan Tracking mode, the current implementation of this feature doesn't do anything on my bios

4- is there any documentation out there dedicated to HP z4 g4 motherboard? No, the most information I could find about this system is "Maintenance and Service Guide"
5- where the ambient sensor is located on the board? older HP models like HP Z420, had this sensor hidden inside the power cables that connect to front power button to mainboard, in HP Z4 G4 it wasn't there and I still couldn't find it (if you read this and find the sensor location, please comment on this post)

6- is there any extensions to add temperature probs to the systems and use it for controlling fan? No

7- and finally, is there any application that can help me manage the ventilation of this system and be able to control front fan speed? you can use an Arduino as a fan controller,  Argus monitor  can read your GPU temperature and use it to control the fan or fans you attach to Arduino, that will be separate fans that you install on your system not the ones that bios controls