It likely isn't.. but if you want me take a wild guess on why it could possible be the CPU... A failure in the ALU, only happens when a certain instruction is called. I don't see the point in taking wild guesses honestly, narrowing it down by swapping in/out components seems more fruitful.
I think I've only ever warrantied one CPU (IGP failure)... but dozens of mobos in the last few years. We typically don't have discrete GPUs in our setting.
Order of things I think it would be given the error code:
1) GPU GPU GPU, very strongly GPU
2) PSU (when I seen the name Rosewill, you better believe it was the first thing I researched.. it has overall high marks though)
3) Motherboard / RAM
4) CPU I guess