Our usual testing regime runs a minimum of 24 tests on each PSU, stressing them from ultra-low load to full capacity. However, given the 1,600W capacity of this monster and 1,200W practical limit of our Chroma test equipment, we haven't been able to run the usual battery.
Appreciating this, but still wanting to provide you with numbers that test the forward-looking features of this model, we have run six benchmarks that take average readings into account, up to a maximum 75 per cent (1,200W) of capacity. We have also done the same tests on two well-reviewed, high-wattage units from Corsair and FSP that feature 80 PLUS Platinum efficiency. We consider these to be benchmark PSUs at the premium end of the market.
The first graph looks at average 12V line regulation from 10 per cent load through to 75 per cent load for the trio of supplies. Anything below two per cent is good, under one per cent is stellar. The 0.14 per cent regulation from the AX1600i is nothing short of remarkable, and it's reasonable to assume that the all-digital nature of the supply means that it is modulating effort on the fly. For all intents and purposes, the voltage doesn't move off 12V.
Even running cross-load tests, where the 3.3V, 5V and 12V lines are loaded in ways that push engineering, show rock-solid stability. The AX1600i is eerily consistent. While you won't necessarily notice this in a consumer environment, this model feels like a server supply in enthusiast form. As it should for the £400-plus street price.
You may wonder, as we did, why the AX1600i doesn't ace this chart, given that it is the only one with 80 PLUS Titanium efficiency. One plausible reason is that running, say, 20W and 40W, which we did, is such a small percentage of total load that the supply cannot hit high efficiencies. Our numbers actually show that it quickly gets better than the other two at 80 and 100W, so it really needs >100W (six per cent load) before it is properly warmed up.
This is better - the supply is able to stretch its Titanium legs as we run from 100W to 1,200W. It peaks at 96.3 per cent at about 60 per cent load - the highest we've seen to date.