This thread has got me curious. Did i add too many fans? So let's find out.
My PC has a similar set up as OP diagram.
Although the first 2x 140mm fans at the front intake have a 280mm radiator.
First, I tested the system with the top 2 exhaust fans
ON. Then tested with the top 2 exhaust fans
OFF.
When I unplugged the two fans on top, I also closed off the top exhaust with the included panels!
Lets start with Ambient Temperatures
Outside PC -
26.7 °C | Inside PC -
28.0 °C
On to the CPU Stress Test
First, I fired up AIDA64 and ran it for about 5 mins to see what the temperatures are in the case plus the CPU temps in HWiFO/CAM. Only 5 mins because the thermometer will switch off after 5 mins.
Fans ON | Fans Off
CPU (Tdie) 72.3°C vs
72.5°C
Liquid Temp -
39°C vs
40°C
VRM T1 -
88°C vs
96°C
VRM T2 -
72°C vs
76°C
Inside Case -
33.3°C vs
34.5°C
Note: From this not so scientific data, I can conclude that having the exhaust on top to push the warm air out has helped the VRM Temperatures much more than other components. CPU temperatures aren't affected as much because it is cooled by a liquid cooler and an increase in temperatures inside the case doesn't affect it.
Now to the GPU!
For the GPU, I ran a total of 15 mins. The 1080Ti is overclocked and overvolted to the max I could go. +50 MHz Core, +450Mhz Mem, +100% Voltage, +117% Power Limit.
Fans ON | Fans Off
GPU Clocks 1987MHz vs
1974MHz
GPU Temp -
71°C vs
77°C
CPU Temp -
45.8°C vs
49.6°C
Inside Case -
38.5°C vs
40.0°C
Note: GPU is the biggest contributor to heat in the system as it pushes hot air into the case. With the top exhaust fans ON, the hot air is quickly pushed out of the system, giving the GPU cooler air to breath instead of the hot air circulating in the system.
So, conclusion. No, it is not overkilling to put that many fans. Haha.