Some reports reports are coming in that some issues exist with the Gigabyte GP-P750GM and GP-P850GM power supplies. Evidently there has been cases of smoke suggesting a component is overheating. I would also like to dissect one or two to see what is wrong with it. Gamer’s Nexus wants to their hands on some to see what is wrong with them
Earlier some NZXT H1 machines also aught on fire. Scary for somebody who leaves their rig on 24/7. It appears that in this case the riser was at fault.
Discussing the issues with colleagues we are in agreement that Gigabyte PSUs are not a very desirable brand right now. Maybe if they redesigned their PSU to be more reliable it would be more popular.
Hardcore Games has used Corsair only for one reason, they came well recommended and they do not fail very often. Corsair offers higher rated power supplies suitable for dual graphics cards which work fine. The HX1000i can handle even the RTX 3090 SLI fine.
Power Supplies usually are fairly well made now. Designs are mature and the technology is posted widely in manuals and on blogs. Designs on this site use bipolar devices but the industry changed to MOSFET in the 1980s.
About the only case where a problem could occur today is if there was a supply problem with components. Regulators are all mounted in metal plates to dissipate heat. The same for power transistors.