Here is 'the fix' according to the Admin over at Collatz: "The "fix" would be removing the Brook+ app and installing a much slower OpenCL version which means fewer credits for you and less work done for the project. I am hoping AMD gets their OpenCL performance issues straightened out before they cease all CAL/Brook+ support." This affects the AMD 4XXX series cards the most right now.

The next release now that the server is up will replace the CAL application with OpenCL. However I've done some hackery so that the actual IL kernel that runs is essentially unchanged and is as fast as the old one.