Hi! I currently have this build using the GT502 case.
I just recently got 3 more case fans. Previously it was set up like this:
I think that for some reason the temps got worse and the PC much louder. It might just be buyer’s remorse but I got more fans so that they could use less RPM and be quieter, but I feel like the complete opposite has happened.
Can I change anything about this layout to optimise airflow? I was thinking of maybe switching the side panel fans to exhaust? That might starve the CPU cooler, though…
Maybe I’m just imagining things and I just need to perform exact tests to figure it out. What do you use for testing airflow effectiveness?
UPDATE:
The issue was weirder than I would’ve thought. The bottom 3 fans are controlled by one motherboard channel using a PWM splitter cable. The rear and side panel fans are the same - one channel for all 3. Previously I had just the rear exhaust plugged in to a single channel but now it’s plugged into the splitter.
Apparently the order of the fans in the splitter is VERY important. I changed it so that the rear fan is the first in the splitter and that instantly fixed the issue. ¯\_(ツ)_/¯
Try this setup:
Tl;dr:
With this proposed setup, aim for slight positive pressure by setting your exhaust fans at a higher speed than the four intake fans (e.g., exhaust - 900 rpm, intake - 800 rpm). This may give you the best balance in noise, cooling, and airflow.
Advantages of this new setup:
Explanation for changing your setup to my proposal:
Mount the top exhaust fan as far left as possible (over the top left corner of the motherboard). The ideal airflow pattern in any system, not just computers, is to get air in at the same rate as you get air out. The ideal is neutral airflow where there is no pressure buildup in a case - air leaves as quickly as it comes in. The next preferable pattern is positive pressure - simply because it helps to reduce dust - where a slightly higher volume of air is brought in than exhausted.
With your current setup, you have too much positive pressure, which is very bad for cooling. You’re introducing an unnecessary volume of air that’s bouncing around in that case. While it sounds like shoving more air into the case would be great for cooling, the problem is that air isn’t leaving the case fast enough! So what happens? You’re shoving so much air into that case at such a fast rate, and it has nowhere to go! Sure you’ve got one exhaust fan that’s trying to pull some air out of the case, and I guess you have some breathing holes at the top, but there’s nothing up there to direct that air, so air will partially get pushed out of there slowly. Meanwhile, you’re still shoving so much air into the case. Air is also forcibly shoved everywhere in the computer, gets pushed in all the cracks and crevices in that case (e.g., between the glass and the case), and small amounts of air get squeezed out from those cracks. The air in the case is somewhat trapped and it actually gets hotter since it can’t exit quickly enough! Your CPU and GPU heat up the intake air, and this is why your temps are worse by adding those three intake fans. You need to get the hot air out at the same rate it is coming in, and exhaust fans will do that for you.
Key: The air coming in should leave the case at the same rate. A compromise, where the only benefit is to help reduce dust, is to have the air leave the case at a slightly lower rate than it came in.
You only need to adjust your setup so you have two exhaust fans: one rear and one top. You’ll see other builds with three fans mounted on the top for exhaust, but that is extremely wasteful and misguided. Those extra fans end up exhausting cool intake air before it even has a chance to flow over the motherboard and other hot components.
Set your exhaust fans slightly higher than the speed of your four intake fans to help balance them out. It is two exhaust vs four intake, so you can try something like this: intakes at 800 rpm, exhaust at 900 rpm. Of course, set up appropriate fan curves when you’re introducing load to the CPU and GPU so they ramp up appropriately.
As for optimization, your definition of noise may be different from others. Introduce sustained load to your PC, and then while you have that load, play around with your fan settings to figure out what you’re comfortable with and set the fan curves appropriately so that they gradually ramp and stay at consistent speeds.
Wow, thank you for such a great explanation!
I will probably first try switching the side panel fans to exhaust, just because it’s much easier and might help level out the pressure. If that doesn’t work, I’ll definitely try your proposed layout!
Happy to help! I don’t recommend you do that, though. You need cool intake air to reach your motherboard and CPU. If you switch those three side fans to exhaust, there is no more cool air reaching your CPU and motherboard. The only air that will reach the CPU is the hot air from the GPU.
Late to the party, but if you do turn your bottom fans around, remember to keep the desk/floor/whatever your PC is on clean. We can all pretend to actually clean the bottom filters regularly, but we know that’s not true and the filter will turn into a wall in a few weeks. Also why my only intakes are on the front where the filter is just magnetic.
@Ansis@iusearchlinux.fyi - I’ll add my setup just as a reference point.
I have been very happy with the level of cooling and have set up the fans to achieve slight positive pressure. This case supports side fans, but I did not add any since they were unnecessary and would just introduce more noise with less benefit.
Pardon the dust and bad lighting - it is overdue for a cleaning but I hurt my back a few months ago and I can’t lift my computer safely to bring it outside and blow my computer air duster through it. Plus the darkness helps hide the dust. 😉: