Passive build in a very slim case

Yes, the Dremel rotary tool had to be used, and the mighty i9-9900K had to be undervolted since the Arctic Alpine 12 CPU cooler is designed for 47W TDP. But ultimately, this build works just fine and even include a modified NVIDIA T400. "There was a desire to make this a fanless build. MSI GT 1030's (which also has 30w TDP) passive cooler is used. The screw mount position is perfectly matching with T400. GT 1030 (GDDR5 version) only goes up to 2GB, and I needed more than 2GB RAM. T400 offered the same low power consumption while doubling the GPU memory. Temperature for CPU can get up to around 80C and GPU up to 85C for heavy load in my case. GPU does not throttle, which is great. The ambient temperature is 24C." Special thanks to Kazuki for this awesome build.

Source: PCPartPicker