There currently is no console support for Linux. I believe that there needs to be an X Server running for OpenCL to work correctly. If X is already running and you still get bad results, try redirecting your display to your host machine.
(I am not a Linux expert.)
The X server is running, and it does work the same except for the 0 Mhz thing.
Hmm weird! I'll file a bug. Thanks for reporting the issue.
Mind providing some more info? GPU, Linux version, driver version, SDK version, etc. Thanks!
Right now it is happening on one system running Ubuntu 11.10 x86_64 with Catalyst 12.1 on a Radeon 4870, and on another Ubuntu system for both a Radeon 5870 and 7970 using the special 7900 driver from http://support.amd.com/us/kbarticles/Pages/catalyst121linuxdriver.aspx
Max clock frequency: 0Mhz
Name: ATI RV770
Vendor: Advanced Micro Devices, Inc.
Device OpenCL C version: OpenCL C 1.0
Driver version: CAL 1.4.1664