I wrote a kernel and I’m currently testing it for performance. Therefore I put the kernel invocation into a loop (1000 times) and measure the time.
After every kernel launch I check for errors.
Occasionally I get an error message:
unspecified launch failure in prior launch
After that the gpu seems to run at 40 % of it’s normal speed. All kernels where I check performance are at 0.4 of their normal execution rate.
To get back to normal performance I do tried to restart X (along with the nvidia driver) which has no effect. Only a reboot helped.
I monitored the core temperature with the nvidia-settings tool and it never reaches the slowdown threshold of 115 C. Maximum core temperature was beneath 70 C.
GeForce 8600 GT
Only certain kernels show this behaviour occasionally.
Any help is appreciated