Why are Fractal Design cases like the Torrent not as impressive for GPU temps?

[zfz]

Why do the some of the best Fractal Design cases with excellent cooling for CPU have less impressive temps for GPU? In particular, cases like the Torrent/Torrent Compact is comparable if not better in CPU temp to cases like Lian Li Lancool II Mesh and Phanteks P500A (which are at the top for both CPU/GPU), but is consistently hovering around average to below average in GPU temps among great airflow cases. [Torrent Compact is consistently 3-6 degrees warmer](https://www.youtube.com/watch?v=oGBQcYvsgFM&t=1154s) than these two cases and even the larger Torrent being an apples-to-apples comparison with its 3 fans is 5 degrees warmer.

All 3 cases only include 3 front intake fans (edit: I did not realize the Torrent includes 3x 140mm bottm intake fans for the GPU) (2 larger fans for the Torrent Compact) that is used for the best and nothing else so it's a pretty even comparison. Just curious with regards to design since all 3 cases are really similar. Actually, if you look the benchmarks, Fractal Design cases in general rarely do great in GPU temps (average to slightly above average in most cases) even if they are great with CPU temps.

To be clear, the case is certainly great overall and GPU temps are above average in general, just that there's a clear difference in GPU temp between other top cases that excel at both CPU and GPU. Actually, pretty much all FD cases have underwhelming GPU temps when you consider their simple mesh designs with front intakes. I don't see any obvious areas of improvement. I don't think it has to do with the front filter because CPU temp is still excellent. In fact, I would think noise-normalized thermals test (most practical/realistic test by GamersNexus IMO) would favor the Torrent best because of the massive fans which should blow more air while also being quieter. Fractal's fans are quite decent.

 

[Chrispy_]

If I had to guess, it's because the cases with bottom-mounted AND front-mounted fans overwhelm the GPU fans.

Look at any GPU cooler; Half of the hot exhaust air exits the fin stack on the top edge, the other half on the bottom edge. If there's too much direct airflow and high positive pressure underneath the GPU, I'm thinking that it does one or both of two things:

1. The GPU fans pushing air through the lower half of the GPU fin stack are being countered by an area of relatively high pressure caused by four 120mm fans all aimed at one location that is sandwiched between the GPU's PCB and the motherboard. This simply results in lower airflow rates through the lower half of the GPU fin stack. To massively oversimplify it, imagine blowing into a tube from both ends at the same time. In this case, the tube represents half of the GPU heatsink, and you have GPU fans blowing into one end and case fans blowing into the other end. The net result isn't actually a deadlock because that's a grossly oversimplified model, but you get the idea....
   
   
2. Hot exhaust air from the lower half of the GPU fin stack doesn't have enough momentum to overcome the fast flow of air directed right at the GPU intake fans, so it does't get expelled far enough away from the GPU to dissipate into the larger case volume. Instead, it's entrained back into the GPU fans raising the temperature of the intake air for the GPU.

Ensuring the hot air escapes is significantly more important than getting cold air to the intakes. IMO cases like the Torrent focus too much on the latter without considering the implications on the former.

I've not been a practising engineer for two decades, but I do have an engineering degree and wrote a dissertation heavily leaning into thermodynamics and fluid mechanics, so my guesses aren't 'wild' guesses, they're based on a few years of hard studying, a two-trimester project, and several exams modules. You should still take what I say as guesswork though, it's literally just that.

 

[oxrufiioxo]

I like Gamersnexus and watch most their case reviews but they gear most reviews towards stock configuration of the case which isn't very useful imo. A good example is the 011 XL comes with no fans so they only populate 3 which nobody buying the case will do.

As far as the FD Torrent results my guess is the top design with the psu blocking all the majority of the exhaust other than the rear fan is the main culprit in my 011 XL if I turn off the top fans while stressing my GPU the temps go up quite a bit even with the single rear exhaust while turning off the side intake makes no difference turning off the bottom intake jumps temps again quite a bit.


Gamersnexus also continues to use very low end hardware throw a 4090 and a 13900k in some of those smaller case and they will be terrible even though they score well with a quad core and a 970.....

 

[agent_x007]

They are using what they had up to this point.
If they "throw it out", they will have re-test ALL cases they already have data for up to this point.

 

[oxrufiioxo]

They are using what they had up to this point.
If they "throw it out", they will have re-test ALL cases they already have data for up to this point.

I totally understand why they are using it I'm just pointing out taking their results with low end hardware by todays standards and applying the results to somthing that consumers 50-100% more power won't give you the same results so while their reviews are good for comparison at a baseline a lot of how they test doesn't really apply unless you are going air cooling with lowish end hardware.

 

[Chrispy_]

Gamersnexus also continues to use very low end hardware throw a 4090 and a 13900k in some of those smaller case and they will be terrible even though they score well with a quad core and a 970.....

It doesn't matter how high their test load is, that just changes the absolute temperatures of their test - You only care about the relative results.

 

[80-watt Hamster]

If I had to guess, it's because the cases with bottom-mounted AND front-mounted fans overwhelm the GPU fans.

Look at any GPU cooler; Half of the hot exhaust air exits the fin stack on the top edge, the other half on the bottom edge. If there's too much direct airflow and high positive pressure underneath the GPU, I'm thinking that it does one or both of two things:

1. The GPU fans pushing air through the lower half of the GPU fin stack are being countered by an area of relatively high pressure caused by four 120mm fans all aimed at one location that is sandwiched between the GPU's PCB and the motherboard. This simply results in lower airflow rates through the lower half of the GPU fin stack. To massively oversimplify it, imagine blowing into a tube from both ends at the same time. In this case, the tube represents half of the GPU heatsink, and you have GPU fans blowing into one end and case fans blowing into the other end. The net result isn't actually a deadlock because that's a grossly oversimplified model, but you get the idea....
   
   
2. Hot exhaust air from the lower half of the GPU fin stack doesn't have enough momentum to overcome the fast flow of air directed right at the GPU intake fans, so it does't get expelled far enough away from the GPU to dissipate into the larger case volume. Instead, it's entrained back into the GPU fans raising the temperature of the intake air for the GPU.

Ensuring the hot air escapes is significantly more important than getting cold air to the intakes. IMO cases like the Torrent focus too much on the latter without considering the implications on the former.

I've not been a practising engineer for two decades, but I do have an engineering degree and wrote a dissertation heavily leaning into thermodynamics and fluid mechanics, so my guesses aren't 'wild' guesses, they're based on a few years of hard studying, a two-trimester project, and several exams modules. You should still take what I say as guesswork though, it's literally just that.

I just helped a friend built a Torrent Compact-based system. The Torrent series in its default config is set up kind of like a positive-pressure wind tunnel: Big volume in through the front and out the back. The bottom grille complicates this, of course, but I wonder if he could be convinced to experiment with those front 180s reversed, considering actual wind tunnels operate on negative pressure.

 

[TheinsanegamerN]

If I had to guess, it's because the cases with bottom-mounted AND front-mounted fans overwhelm the GPU fans.

Look at any GPU cooler; Half of the hot exhaust air exits the fin stack on the top edge, the other half on the bottom edge. If there's too much direct airflow and high positive pressure underneath the GPU, I'm thinking that it does one or both of two things:

1. The GPU fans pushing air through the lower half of the GPU fin stack are being countered by an area of relatively high pressure caused by four 120mm fans all aimed at one location that is sandwiched between the GPU's PCB and the motherboard. This simply results in lower airflow rates through the lower half of the GPU fin stack. To massively oversimplify it, imagine blowing into a tube from both ends at the same time. In this case, the tube represents half of the GPU heatsink, and you have GPU fans blowing into one end and case fans blowing into the other end. The net result isn't actually a deadlock because that's a grossly oversimplified model, but you get the idea....
   
   
2. Hot exhaust air from the lower half of the GPU fin stack doesn't have enough momentum to overcome the fast flow of air directed right at the GPU intake fans, so it does't get expelled far enough away from the GPU to dissipate into the larger case volume. Instead, it's entrained back into the GPU fans raising the temperature of the intake air for the GPU.

Ensuring the hot air escapes is significantly more important than getting cold air to the intakes. IMO cases like the Torrent focus too much on the latter without considering the implications on the former.

I've not been a practising engineer for two decades, but I do have an engineering degree and wrote a dissertation heavily leaning into thermodynamics and fluid mechanics, so my guesses aren't 'wild' guesses, they're based on a few years of hard studying, a two-trimester project, and several exams modules. You should still take what I say as guesswork though, it's literally just that.

The greatest sin of modern case design is the complete avoidance of side fans. All the PAP in the world wont help you if your exhaust sucks.

There's a reason that even at 320w power draw my 6800xt sits at 70c, with the fans at 50-55%. That reason is the side fans. The heat that pours out the side is incredible, and I'm sure that most modern cases would see much higher temps simply because that heat would recirculate.

IIRC on the old Gamer Nexus website they had a compilation of CPU and GPU temps based on case, and while some modern cases were a bit better for the CPU, the then 14 year old HAF X dominated GPU temps by nearly 20c over the next best. It was the only case with side exhaust fans. In todays world of 400w+ GPUs, we need more cases with side fans, less glass and bling, more functionality.

 

[LifeOnMars]

I'm using a Meshify 2 Compact with all the filters in place and have a 390w 3080 12gb. 5700x is at stock. It's an extremely quiet setup. Playing at 4k maxed in games that can push that full 390w (rare when vsynced at 75hz), temps never go above 70c with a fan curve that settles around 60% and is near silent. It helps in my case (pun intended) that the end of the GPU practically touches the front case fans (mms of space) and i have an intake fan below pushing in cool air which is fed directly to the GPU fans. (The majority of the time its in the low 60s or high 50s)

I just think temps can vary with each and every setup and it's about finding the right config of fans and hardware within a case that can help determine the best outcomes. Sometimes that's just not possible. PC part picker is a good site to look at full setups and what temps they are getting and with what combination of hardware.

 

[oxrufiioxo]

The greatest sin of modern case design is the complete avoidance of side fans. All the PAP in the world wont help you if your exhaust sucks.

There's a reason that even at 320w power draw my 6800xt sits at 70c, with the fans at 50-55%. That reason is the side fans. The heat that pours out the side is incredible, and I'm sure that most modern cases would see much higher temps simply because that heat would recirculate.

IIRC on the old Gamer Nexus website they had a compilation of CPU and GPU temps based on case, and while some modern cases were a bit better for the CPU, the then 14 year old HAF X dominated GPU temps by nearly 20c over the next best. It was the only case with side exhaust fans. In todays world of 400w+ GPUs, we need more cases with side fans, less glass and bling, more functionality.

The Cooler master 690 ii had a similar setup... I ran both 680 sli and 970 sli with excellent temps in that case. Pretty sure my 011 Dynamic XL would outperform it though handles a 450w gpu load pretty easily.

 

[freeagent]

Maybe the problem is noise normalized testing?

Crank up the fan speed and you will get good results. I came from an extremely well ventilated Meshify C that was extreme overkill and now running Torrent Compact with the stock fan setup for now. It’s nice and quiet and performs strong. By quiet I meant not as loud as my last setup

 

[oxrufiioxo]

Maybe the problem is noise normalized testing?

Crank up the fan speed and you will get good results. I came from an extremely well ventilated Meshify C that was extreme overkill and now running Torrent Compact with the stock fan setup for now. It’s nice and quiet and performs strong. By quiet I meant not as loud as my last setup

lol, I set up my 011XL with 7 Phanteks T30-120 and 3 ML120 PRO for the opposite reason so that while I game I can't hear my PC.... fans barely need to spin past 600RPM to keep my gpu/cpu cool....