I have a performance problem of Device to Host memcpy in Tesla.
It takes 5 sec to copy 1GB. It’s too slow.
The same code works fast in other GPU. This problem only happens with a Tesla.
Is it likely because of lack of electric power?
But strange thing is the only slow part is D2H memcpy. Other operations such as H2D memcpy and numerical computation work well.
Can this symptom be caused by lack of electric power?
We tested again with the same GPU, another mother board and another power unit which supplies enough power.
As a result, a slow-down has not been observed. Accordingly we concluded the problem is because of insufficient power supply.
I did not know that if power supply is not enough, a GPU goes slow instead of hanging up.