ASUS X370-PRO with Tesla P40??

Hiiii,

Does anyone know if this should work? I have a ASUS X370-PRO on the latest firmware and a Tesla P40. Have cabled the Tesla P40 in with a CPU power connector (from an EVGA 750W PSU) but it won’t boot when it’s connected. PC boots fine when GPU is disconnected. CPU is a Ryzen 7 1700.

Have done some research and seen people mentioning disabling 4G Decoding and CSM in the BIOS. I don’t seem to have 4G decoding but do have CSM. I disabled that but it didn’t help.

Any suggestions would be much appreciated!