$50 is a (
It's actually $65
Is this $90 one from Fry's a fake also?
search this at Fry's
CX750 is Different from TX750 or CS750M. Choosing a power supply on price and single watts alone leads to unhappiness and failure.
170W on the 3.3v/5v rails, 15 to 20W on the +5vsb and 375W minimum on the 12v rails is a requirement for proper operation of sandy bridge and haswell based systems. The 130W on the 3.3v/5v rails is under powered by 40W and the +5VSB is under powered 5W
Theres more than enough on the 12v rails at the expense of the others. If you get 750W on the 12v rails you have ZERO watts for everything else.
So no $90 is likely not fake. $50 or $65 absolutely is fake. As I Said I could see from the pictures that they were fake but I'm not going to get into why I could tell for a few Dollars more you get a MUCH Better Power supply in the TX750 or CS750M. The "Issue" with the CX750 is that it is NOT EPS12V 2.92 certified. Its also LOW LOW LOW END on the ATX scale which is why they don't say ATX 2.4.
Note on the Label for the Dell that they provide 20W on the 5VSB.
If you add up all the currents its more than 305W but Dell does not overstate the total output of the supply.
5V @ 22A = 110W
5VSB @ 4A = 20W
3.3V @ 17A = 56.1 W
12V @ 36A = 432 W
-12 @ 1A = 12W
630.1 W Total on 305W power supply.
80 percent of 750 = 600W
80 percent of 550 = 440W
This means that 550W supplies for some dell models will not even turn on the machine due to lack of power in specific areas.
And no supply is 100 percent efficient.
This is why I recommend an EPS12v Corsair CS750M
DELL's 525W power supply Guarantees 150W on the 3.3v and 5v Rails. But also again Rates the 5VSB at 20W.