RE: Dell Inspiron 3847 PSU upgrade
The issue is that 25 amps * 5v = 125W some supplies that people are complaining about have a rating of 20 AMPS aka 100W on the 5V rail. You cant get max output on all the rails at the same time. Many people balk at 500W being too small because they look at the supply as a single 12v rail and disregard everything else. The spec is misleading if you look at total. 744W means 6W for everything else. The opposite end of that is that if it needs 25A on the 5v rails it wont shut down. Supplies are not linear and use max amps continuously.
CX500 for example
+3.3V@25A, +5V@20A, +12V@38A, -12V@0.8A, +5VSB@3.0A
DELL YN637 525W T3400 power supply
This works fine with specific Geforce 960 from evga.
But that does not mean all 500W power supplies are created equal. +5VSB is 4A and the combined says 150W for the 3.3v/5v