I just recently purchased a Lenovo M91p desktop, the PC will not boot when I have my HD 7950 plugged in but will boot when I run off integrated or my GT 610. This was tested on both an XFX TS 550 and a Lepa N500 PSU, both could handle an fx 8320 and hd 7950. I have never had this issue with this graphics card in the past, it even worked in an HP Pavillion P6-2003w.