Antec’s EarthWatts EA-750 Green PSU is a slightly puzzling product in that it’s described by Antec as being ‘one of the most environmentally friendly power supplies available.' The only credential Antec uses to back up this claim, however, is that the PSU sports the 80Plus Bronze certification, something that nearly all the other PSUs in this group test either match or better. As a result, we can’t help thinking that the Green branding that the PSU carries is just a calculated marketing ploy.
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Aside from these claims on the box, the EA-750, like the Antec High Current Pro HCP-750 we look at next, is made to Antec’s designs by Delta, and is a relatively uninteresting affair. Its cables are captive, meaning that you’ll have to hide them somewhere in your case, and only the 24-pin ATX cable is braided, which is a little disappointing for a £70 PSU.
As with most of the 600W+ PSUs on test, the EA-750 spreads its 12V power delivery over a number of rails – in this case, there are four. Each of these is rated at 40A, with the PSU being able to supply its entire maximum rated output of 750W across just these four rails if necessary. The PSU’s connections are sensibly split across the rails too, as the 24-pin ATX and 8-pin
12V ripple at 50 per cent load
12V ripple at 100 per cent load
EPS12V connections have a rail each, while the remaining two rails power a pair of 6+2-pin PCI-E connectors apiece. Meanwhile, the remaining SATA and Molex connections are bundled onto the same rail as the 24-pin ATX connection.
The EA-750 remained composed during our battery of tests and managed to output extremely steady voltages across all its rails. What's more, it did this regardless of whether it was loaded at 10, 50 or 100 per cent of its maximum power output. It also remained relatively quiet during testing, only becoming audible when outputting its full 750W of power.
Its efficiency results, on the other hand, were disappointing for a PSU that Antec claims is focused on environmental responsibility. It was 87 per cent efficient at half load and 84 per cent efficient at full load, figures that are well behind the 92 per cent and 90 per cent efficiency figures we saw from the Antec High Current Pro HCP-750. This meant that at full load, the EA-750 had to draw 50W more than the High Current Pro 750 to output the same 750W, which is hardly a good result for the environment.
On a more positive note, the EA-750 performed well in the more subtle holdup and ripple tests. Its holdup times on the two rails we tested either matched or exceeded the 17ms recommended by the ATX spec and its ripple amplitude of 15.5mV was one of the best we saw. Unfortunately, these results don’t disguise the fact that £70 is quite a bit to pay for a PSU without any premium features and average efficiency.