HP ProDesk 400 G3 MT case fan speed control

[ShimmyZigZag]

Hello, i have a HP ProDesk 400 G3 MT. Recently I upgraded the gpu to GTX660TI, and also put there new PSU- Corsair VS550. After that, the PC runs very well, but when i stress GPU at max, the temperature is about 70ºC (which is normal for this kind of a gpu), but the case fan starts spinning at 100% (PC probably thinks the gpu is overheating). Is there a way to reduce case fan speed, when gpu gets hotter? Because the noise is kind of annoying. 

[NonSequitur777]

@ShimmyZigZag,

Welcome to our HP User Forum!

The issue you described -in my opinion, is most likely related to the air-cooling dynamics (or lack thereof) inside your ProDesk 400 G3 MT.

What I would try first is the following: as your GTX 660 Ti is a 2-slot graphics card, remove the two remaining PCIe brackets (shown within the red square) -if you haven't removed them already, to improve airflow inside your desktop next to your graphics card:

However, if this doesn't work, a more radical modification -one I have quite successfully applied to a number of my legacy HP Desktop Upgrade projects, is to add an additional chassis fan, situated directly above the CPU heatsink/cooling fan assembly, as I did with my HP ProDesk 600 G3 MT upgrade project: https://h30434.www3.hp.com/t5/Desktop-Hardware-and-Upgrade-Questions/Upgrading-HP-ProDesk-600-G3-MT/...:

Please Note: Not all the mods shown in this link necessarily apply to your desktop. I substantially changed the air-flow dynamics to best suit my particular 'case':

1.) I added an oversized/modified CPU heatsink/cooling fan assembly, which blows air to the front.
2.) I added a cooling fan blowing air in on the outside of the case, because the oversized CPU heatsink didn't provide enough space to allow the cooling fan to be installed inside the case.
3.) I moved the stock chassis cooling fan from the inside (to create more space inside the chassis) to the outside of the chassis AND turned it around to blow air in.

In your case, I would think there is sufficient space inside your MT desktop (with the stock CPU heatsink/cooling fan assembly) to add the second chassis fan inside your removeable panel to blow air in.

If this is something you want to take on, let me know, and I will give you the part numbers you need and where to purchase them.

DISCLAIMER 1: This modification assumes that you are an experienced Do-It-Yourselfer, that you work safely and that you have the tools and experience necessary to make this modification.

DISCLAIMER 2: HP does NOT approve of, let alone recommend this kind of mod. You do so at your own risk and volition and assume all responsibilities for any injury or loss resulting from implementing this mod.

DISCLAIMER 3: This modification may not solve your issue.

Kind Regards,

NonSequitur777

[ShimmyZigZag]

Thanks for the info. 

I was thinking about swapping whole case, for standart midi tower with two front 120mm intake fans and one 120mm rear fan for blowing air out. When i done it, i will post some pohotos. 

[NonSequitur777]

@ShimmyZigZag,

That should work -pushing more air through your case would benefit cooling down not just your CPU but also your graphics card.

Kind Regards,

NonSequitur777