Need help with the share direct setting for graphics

I just started a new job where a cluster of ESXi 6.0 host were deployed with NVIDIA telsa10 cards. I need to get the settings on the host to use the “share direct” mode because in its current state only 12 VM’s can power on at the same time.

However, the edit settings button under graphics configuration on the host is greyed out. I had vmware support verify basic settings as well as the driver for the card. Please help.