I've recently switched from a 500w coolermaster PSU to a 600w pc power and cooling silencer III after a CPU and GPU upgrade. With the new PSU, my USB devices charge much slower (iPhone didn't even reach 75% from 40% overnight). Everything else seems working as usual. Ideas? Thanks.
Did you change the motherboard? A standard USB port is limited to 500mW and that's not much to load an iPhone or any other device. Some motherboard provide more power on some of there USB ports, typically the plugs for the front panel.
The motherboard is the same. Front ports were charging very well with old PSU. Part of one of the advertised benefits initially of the board was the ability to effectively charge USB devices even when the computer is shut down.