High system interrupt with K40c

Hi there,

Current system setup uses a Quadro K6000 + a Tesla K40c, graphics card driver is the latest 430.86, however, the problem is adding Tesla K40c to the system causing high system interrupt, and making the system very sluggish.

Both GPUs can be recognized by the Windows Device Manger and Nvidia Control Panel.

It is a HP Z840 with 1124w power supply. For Tesla K40c, I use 1x 6pin cable and 1x 8pin cable (converted from 6pin cable using HP branded converter).

Any ideas what causes could be?

Thanks in advanced.