Antec actually has several 550W models on the market, which can be a little confusing, but the key here is â€œHEâ€ which stands for High Efficiency. It had a quoted efficiency of 85 per cent which is very high. The more efficient a power supply is, the less it will cost to run â€“ so this is a good thing.
Uniquely, this is the only power supply in the group test that is modular in design. This means you can unplug all the cables you arenâ€™t using. From a systems point of view this is just adding more points of failure, but from an Enthusiastâ€™s point of view, this is a very handy thing indeed as you can remove unwanted clutter from your case. Each module can be plugged in to the power supply as needed. However, there arenâ€™t actually enough sockets to plug in every cable provided, so some choices must be made on what you want to use. Even if they were all plugged in, there would be a minimal amount of connections, so this is definitely a down side. They are all neatly braided so the whole affair should make for a tidy case.
The PCI-E connectors, of which there are two for SLI use (and certification), both come off the second rail, which is actually a different rail to everything else so that the graphics cards can get as much juice as necessary. Considering each rail is 18A, thatâ€™s not a bad amount at all. The total sum for all three rails is only 42A, so you wonâ€™t be drawing the full amount on each, but it does help balance things evenly.
Testing showed no surprises with stable voltages at each load. Efficiency wasnâ€™t as high as Iâ€™d hoped, managing between 81 and 83 per cent, which is below the stated amount on the box. In our â€œoverclockingâ€ test, the power supply didnâ€™t shut down until 30A. Considering this is supposed to be ATX12V 2.2, it should shut down at 20A. I can forgive a 10 per cent or 20 per cent tolerance, but this seems a little on the high side. This has safety consequences if you are a tinkerer but the fact it actually has cut-outs means you should be safe from electrical fires. Taking that in to account, you essentially have 120W of extra juice should you need to suddenly power more components. Naturally doing so will weaken the power supply over time as it is not designed for such a load.
The biggest issue with this otherwise fairly balanced PSU is the use of an 80mm fan instead of a 120mm, which makes it a little on the noisier side. At Â£75.61 this is amazing value for money, for a power supply that would fit nicely in any machine.