The 0x124 error is usually related to one of the cpu related voltage settings where the voltage is too low.
You can do a web search using: 0x124 whea error for more information.
Your report shows: +3.3V 1,152 V, where the 3.3 volt reading should be within plus or minus 5%.
Double check the voltage reading with other monitoring software.
Can you test with a different video card?
Have you made any recent changes to your system?
Sorry, I'm not familiar with AMD systems or win8.