The only addition to the Dark Base Pro 900 Black rev. 2 from the “be quiet!” computer case I had to make with the new graphics card was the installation of a noctua NF-A20 computer case fan right at the front of the case between the normal front case fans and the hard drive cages.[1] That very large premium quality 200mm computer case fan barely fits in that spot. The other changes that I ended up making after installing the new graphics card happened at the bios level. First, I had to load up the ASUS UEFI bios utility to run the QFan control settings which ended up displaying, “All fan calibrating.” Second, I turned off the XMP element of the overclocking and allowed the CPU to run at its normal out of the box clock speed. My CPU is being cooled by a Corsair water cooling block and it exhausts up and out of the computer case. That means the heat generated by the ASUS TUF Gaming GeForce RTX 3070 Ti 8GB graphics card is mostly centered in the middle of the case. The addition of that 200mm noctua computer case fan to push air directly across the case toward the open back has helped considerably. 

The rear of the Dark Base Pro 900 only has one case fan and that was probably the root cause of the problem. Instead of having the heat exhaust out the back of the case the airflow from the fans at the top of the case was pulling the heat from the graphics card up into the water cooling block area where the CPU heat persists until thermally exchanged by the top fan exhaust. This entire blog post has been about adding one computer case fan. At some point, I’m going to need to take the fan out and file off just a little bit of the edge facing the glass window. I was able to secure the glass wall back on with the four thumb screws, but the fit was very tight and would benefit from a reduction of just a little bit of plastic edge on the noctua fan. 

Footnotes:
[1] Here is a direct link to that noctua NF-A20 fan https://noctua.at/en/products/fan/nf-a20-pwm