I have an Alienware 17. With Ubuntu 14.04 CD, I choose "Try Ubuntu without installing". Then hit enter. "Ubuntu" appears on screen for a short time. Then black screen. Then these messages: radeon GPU lockup CP stall for more than (x msec). radeon fence wait failed. radeon failed testing IB on ring 5.
Graphics card is AMD Radeon R9 M290X. Drivers are current.
What should I do?