I have no clue how you would fit 13, i have 4 installed on my 1950x x399 board with watercooling and its a little tight with all the wires and tubes... im using PEX as my tubing for testing purposes.....

There is room on the bottom level, but not really a lot imo and its not a great high flow air case... to much open space with the amount of fans on the case, server cases push more air compared to this case. My 4U, 4 x 1080ti rig on water runs cooler than the above thermaltake case due to the sheer amount of forced airflow in a tight space. The thermaltake seems to have hot spots in the case even with 3 radiators and fans supporting it.