Ubuntu 9.04 and video-drivers 10.2: OpenCL reporting wrong GPU operating frequency

Discussion created by Fr4nz on Feb 22, 2010
Latest reply on Feb 26, 2010 by omkaranathan


I'm working under Ubuntu 9.04 64-bit with an ATI 5770 and ATI Stream SDK 2.01.


Today I've upgraded videocard drivers from 9.12 to 10.2 and I've noticed that the GPU operating frequency reported by OpenCL APIs is 960Mhz instead of 850Mhz, when querying the GPU about its properties.

In the ATI control center the frequency reported is 850Mhz, which is correct. I've also verified that this "problem" does not depend from the SDK, because also with SDK 2.00 the same wrong frequency, 960Mhz, is reported: before upgrading drivers and SDK, the frequency was correctly reported as "850".

So, my question is: is  this a bug related to the new video drivers or the GPU is really running at a speed >850Mhz ? For me it is important to know this when study running times of my kernels...