This can be marked as solved Pantera it was a case of a slowly dieing Power supply. my gpu kept turning off and on when pushed hard (like Building mode) Thanks for your efforts and keep up the good work. P.s. also gave me an excuse to upgrade a few other bits lol
So my question about your Power supply wasn't completely wrong than. Nice to know that it could be solved for you.
it was running other games fine but not this one lol it eventually packed in once i got some new components fingers crossed