Modder discovers that putting a GPU in the 'wrong place' can deliver a 19 degree cooler hotspot — breaking convention can produce great results despite decades of PC DIY evolution
The absolute best GPU result wasn't good for CPU temperatures, so the tech tinkerer also shared the best overall configuration, optimized for both CPU and GPU.
It might be reasonable to assume that desktop PCs are built in a certain way due to decades of evolution and optimization. However, we're getting used to TrashBench challenging convention, and we're pleased to say the video below represents one of this enthusiast's best cooling innovations yet. In this latest video, completely ignoring the accepted norms of GPU placement delivered up to a 19°C hotspot temperature reduction but adversely impacted CPU temperatures. However, some more tweaking resulted in a 14°C reduction in hotspot temperatures and a 3.3°C cooler CPU.
TrashBench's plan was to prepare his RTX 3080 desktop PC and "test it normally, then start moving s*** around." This process began with an entirely conventional setup with the CPU cooled by a 360mm AIO, and the triple-fan RTX 3080 slotted directly into the usual PCIe expansion slot.
With the traditional build complete, TrashBench tested this baseline with a constant thermal load from looping 3DMark Time Spy and 7-Zip’s built-in benchmark. The fans in the system had their RPMs locked for consistency. Now he could start "trying to figure out if we’ve been putting the parts in the wrong place."
Beginning the first 'alternative' PC build, we heard the modder muse, "cable management isn’t important here... Is it ever?" Then we saw the GPU tested at the bottom of the case, and vertically to the side, facing one way or another, and either side of the triple case fans on the side. Meanwhile, the CPU AiO cooler was tested with the radiator fans pushing air out or bringing air in.
In summary, some configurations mostly benefitted the GPU or the CPU. But, as we noted in the intro, the sweet spot - where a worthwhile benefit was recorded in cooling both the GPU and CPU was still very worthwhile.
Taking the lessons learned from the best GPU and CPU cooling ideas, and striking a balance, TrashBench finalized his reinvented PC cooling design. That was with the CPU mounted vertically, directly against the side intake fans, and the CPU AiO cooler radiator in a traditional exhaust config. See the screenshot for the observed benefits. We’d headline this sweet spot configuration as delivering a 3.3°C cooler CPU and chilling the GPU hotspot by 14°C.
If you want to try this kind of GPU repositioning testing, a PCIe riser cable is essential. We saw TrashBench use them in a number of lengths.
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Mark Tyson is a news editor at Tom's Hardware. He enjoys covering the full breadth of PC tech; from business and semiconductor design to products approaching the edge of reason.
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Fomdoo Unfortunately cases aren't designed to fit a GPU like this and you also have to give up some performance using one of those pcie riser cables.Reply -
EzzyB This is why my last two cases haven't had any glass at all. My current case is a North XL with a mesh side panel instead of glass or acrylic. Buying the case with that particular side panel includes a bracket for two 140mm fans that put outside air directly on the GPU/CPU/VRM area. (Previous case was a Lian Li with one 120mm fan to do the same.)Reply
So, you don't have to do weird things with your components to get the same results, just give up the RGB bling and the headaches it sometimes can cause. While decent cable management is always a good idea for airflow reasons, you don't have to be too anal about it if no one can see it! -
thestryker Pretty much everyone knows direct airflow on the video card improves temperatures. It doesn't particularly matter how you get it and several cases have bottom intake for exactly this reason.Reply -
BillyBuerger The standard ATX GPU as an expansion card in the standard slots hasn't made sense for a lot of years. Especially as GPUs have greatly outpaced CPUs in power usage. There really needs to be a change to allow GPUs to hold a more prominent position in the case that allows for direct airflow for intake and exhaust. Something more similar to what the CPU has.Reply
I personally mounted my GPU to the motherboard tray just like the main board and CPU are. And stuck a CPU tower style cooler on it as well. Both CPU and GPU get direct cool air from the front of the case and can push the warm air out the back. Sturdy mounting and no blowing air over each other. Now, my setup is super low powered as I really have no need for anything crazy hot and more importantly, expensive. But I would love to try this with some actually high end gaming gear to show/prove that it can work. Yes, this would mean new layouts and not following current ATX patterns. But something really needs to be updated to fit the current state of PC parts.
Well, it would if it made any sense for people to buy and companies to invest in these kinds of things. It's too expensive for any of this right now. -
alan.campbell99 Reply
Mine does have the tempered glass side but it's otherwise what I think of as conventional. I had been thinking to ask about this trend towards fishbowl cases that I'm seeing in the retailer here as well as mucking around with positioning the power button/front access ports. I'm used to having the button/ports either top front or on the top front edge but now I'm seeing ones with these either off the RH side of the top case or the bottom front on the LH side This was particularly notable when I was researching replacement cases for SO's PC and none of these positions would suit since the case is currently positioned LH side facing but with a bunch of stuff sitting alongside the bottom of the case. I also wonder with putting the case/radiator fans at the front RH instead of front with no facility to filter means more dust will get into these fishbowl cases?EzzyB said:This is why my last two cases haven't had any glass at all. My current case is a North XL with a mesh side panel instead of glass or acrylic. Buying the case with that particular side panel includes a bracket for two 140mm fans that put outside air directly on the GPU/CPU/VRM area. (Previous case was a Lian Li with one 120mm fan to do the same.)
So, you don't have to do weird things with your components to get the same results, just give up the RGB bling and the headaches it sometimes can cause. While decent cable management is always a good idea for airflow reasons, you don't have to be too anal about it if no one can see it! -
pepe_le_pede I run a 4080super in a HAF700 berserker, GPU temps rarely get above 60°C even on cinematic settings on Pax Dei.Reply -
bit_user Reply
This is what I've been saying. GPUs should come in standard radiator form factors and use MCIO cables for motherboard connectivity (much better, mechanically and electrically, than PCIe riser cables). Then, you just bolt the GPU directly to a radiator mounting point and get virtually the same benefits as if it were water-cooled, but without the additional complexity and expense.BillyBuerger said:The standard ATX GPU as an expansion card in the standard slots hasn't made sense for a lot of years. Especially as GPUs have greatly outpaced CPUs in power usage. There really needs to be a change to allow GPUs to hold a more prominent position in the case that allows for direct airflow for intake and exhaust. Something more similar to what the CPU has.
The way I'd do it is to have both the GPU and CPU coolers exhaust directly outside of the case. That way, your case temperatures would be almost the same as the ambient exterior temperature, which could benefit things like memory. You could further refactor case design by moving the intake to the side of the case, so that the cool intake air hits RAM, the chipset, VRM, and any M.2 SSDs on the motherboard.
To take it a step further, deconstruct the motherboard by putting the CPU and memory on a GPU-like daughter card. Then, you can mount it in the same way as I described mounting the GPU, and completely get rid of any water cooling yet retain all of the benefits. -
bit_user Reply
If the only issue is the power button, you can get external power buttons that plug into the motherboard's power connector header.alan.campbell99 said:as well as mucking around with positioning the power button/front access ports. I'm used to having the button/ports either top front or on the top front edge but now I'm seeing ones with these either off the RH side of the top case or the bottom front on the LH side This was particularly notable when I was researching replacement cases for SO's PC and none of these positions would suit since the case is currently positioned LH side facing but with a bunch of stuff sitting alongside the bottom of the case.
I almost never turn off my main PC. I always just put it to sleep, when I'm not using it.
Dust seems like one of the downsides of those kinds of cases. However, I don't really see why you couldn't have dust filters.alan.campbell99 said:I also wonder with putting the case/radiator fans at the front RH instead of front with no facility to filter means more dust will get into these fishbowl cases?
The bottom fans are really the ones that seem to pose the most issues for dust filtering. Even some cases I've seen which have them on the bottom don't make them easy to remove & clean. -
bit_user Reply
That's average temperature, I think. Your hot spot should be higher than that.pepe_le_pede said:I run a 4080super in a HAF700 berserker, GPU temps rarely get above 60°C even on cinematic settings on Pax Dei.