you mean 3A?

Id expect the voltage to drop more under the load, as it is a transformer-based power supply. but maybe theres more circuitry in that gray brick than I think...

yea 3a, i dunno what the voltage drop is, havent tested it

It shouldn't matter how far the voltage drops under load... it can't possibly dip below 4.5 volts, and as long as it doesn't, the PSU should have enough voltage according to the datasheet... Although that was LM2645MTD datasheet... not the LM2643MTD, like the GC PSU has... but I can't find any info on that one...