Question Trying to figure out the best fan configuration to retrofit in this Dell Precision

[Cyber_Akuma]

I asked about this before, but have since been performing tests... and they have been inconclusive. Yes I know I am overthinking and putting way too much work into this, but I already have all these fans on hand and have spent days trying to figure it out, so might as well go all-in and try to get this situated once and for all.

I have a Dell Precision T5810, it's cooling situation is rather poor. The entire system just depends on three very high CFW and nearly 1-Amp each fans on the front to try to force air throughout the entire rest of the system without additional fans, it doesn't even have a rear fan (Haven't seen a desktop lacking that in 30 years).

Anyway, I tried to put an RTX 2060 Super in it and the card was instantly hitting 80C, and clearly throttling as it never went above 80C and was not performing as well. The side of the case was also getting very very hot, as in "just barely too hot to even touch" hot. Taking off the side panel reduced temperatures by 10-12C on the GPU, so clearly the problem is there, but I can't just run it without a side panel.

So I have been experimenting with adding fans to it, using a temporary wooden panel that I am cutting into to see where would be the best place to put the fans before I cut into the actual metal side-panel.

It's definitely getting a 80mm fan in the rear to get rid of the stagnant hot air the CPU dumps near the rear of the case that just stays there, and I am going to be putting another 80mm exhaust fan under the GPU as well (was considering making this intake but a rear intake would be a bad idea). You can see those in the picture, yes of course the tape is temporary, I will screw them in from the inside once the setup is done.

The SIDE fans are the problem. I have roughly a 130mm wide and 180mm tall area where I can cut out of the case without it being blocked by any other components either in the case or in the side panel itself. That's enough for a single 120mm, or a 120mm and two 60mms.

I was at first assuming I could just get away with a single 120mm and anything extra would make no difference. I tried testing several configurations using OCCT in Power Test mode to generate heat from both the CPU and GPU at the same time. I tried the 120mm on the topmost position, bottommost position, and both as an intake and exhaust. Wasn't sure what would be ideal since the GPU exhausts air from the side and that's the main issue with heat.... but it also intakes air from the bottom and there isn't much airflow there.

But just to be through, I tried putting those 80mm fans below it and there was a difference, but most of the results in different configurations I tried did not make sense.

So just to make sure I get a complete idea of all the differences in where the air is going, I put the 80mm fans back on the rear, got two 60mm fans, and attempted multiple configurations:

https://imgur.com/IF59Em5

View: https://i.imgur.com/IF59Em5.jpg


I tried with the 120mm on the top and the two 60mms on the bottom, using the two 60mms as a set as if they were a single horizontal fan. I tried both intake, both exhaust, one exhaust and one intake, and then opposite, I tried the 120mm on the top and on the bottom with all of this.

And in all of it, none of the results made any sense! I expected for sure the worst result would be intake on the top of the card and exhaust from the bottom, since that is doing the opposite of what the card wants... and half the time these indeed were my worst temps (many times worse than just having an empty hole with no fans at all) and other times they were good. I tried what I assumed would be the best configuration of the two 60mms on the top to exhaust the hot air and the 120mm on the bottom feeding the GPU's own fans air... sometimes this was good but many times it was worse.

I am extremely confused now and pulling my hair out why none of these results are making sense based on where the GPU is exhausting and intaking air. Can anyone give me some advice on what would be the best way to set this up? I guess that once I cut the holes in my side-panel the position of the 120mm and two 60mm fans is set in stone, but I would still be able to swap which ones are intake and exhaust easily enough.

If it helps, this is what the inside currently looks like (that NVME adapter below the GPU is temporarily and will be removed):

https://imgur.com/Se8RaMG

View: https://i.imgur.com/Se8RaMG.jpg


And these were the measurements I took of where I can put the fans in the side panel, the only realistic place is over that area where the motherboard label is:

https://imgur.com/iOdUlif

View: https://i.imgur.com/iOdUlif.jpg


Can someone help me figure out what would be the best configuration for the 120mm and two 60mm fans I am going to be putting on the side?

 

[king smp]

Hmm I dont know if I can give you a good answer but check out this article about neg vs pos air pressure -
https://www.linkedin.com/advice/0/w...itive pressure,generate more heat than others

Personally i like to get the air out of the case so using them as exhaust fans is generally how I would go.

 

[Cyber_Akuma]

Yeah, I am aware of negative vs positive pressure, which is another reason I don't want to just have everything be exhaust.

 

[king smp]

you could try a infrared thermometer and measure your temps around the case to see if you have any hotspots.

Usually get a hotspot right around the memory/cpu socket

 

[Cyber_Akuma]

The RAM is actually encased with dedicated fans blowing across it (those two black bars with the Dell branding you can see on either side of the CPU cooler). And I have looked around the case before, the heat is all directly behind the CPU cooler and coming out the side (as in towards the side panel) of the GPU.