Back to the original question on power supply efficiency. The 80 plus marketing standard (
https://en.wikipedia.org/wiki/80_Plus) . breaks it down into metal groups. Just plain 80+ being the lowest and titanium being the highest. The rated wattage on the power supply is the output amount, not the input. So a straight up 80 plus 1000 watt power supply at 100% load actually pulls ~1200 watts at its input. For that same wattage a titanium would only pull ~1100. While there is no quality standard involved as a general rule of thumb the manufactures really only produce psus in three of the categories (Bronze, Gold, Titanium). Bronze is typically a value line psu and the cheapest. Gold is mainstream and what you will usually find at big block stores and titanium is manufacturer flagship level. You will find a few of the in between classes out there but they will price accordingly. As the old adage goes you get what you pay for. Titanium level units are usually built the best with the best components (and the most expensive). Again though the 80+ standard does not require any level of quality, only that it can meet the efficiency standards. So while a bronze psu is probably not going to be very good because it is built cheap there are a few very reliable ones out there. In the same vein if you purchase a titanium psu it is probably going to be pretty decent, but some of them are complete junk. The best thing you can do is read reviews on the PSU you are thinking of getting before purchasing. Because of the typical quality to value proposition I never suggest going lower than a gold and recommend getting a titanium even though they are the most expensive. There are only a couple of manufactures out there and many are sticker brands. I like seasonic because they actually produce their own and decent quality. Corsair, while a sticker brand, seems to get pretty decent quality control from their oems.
The power supply is like the foundation of a house. It isn't pretty but if it isn't rock solid nothing else in the computer works. With the latest gpus I would not recommend going below 750 watts and at the very least a gold.