This product is clearly targeted to users that want a real 550 W power supply but don’t want to buy the most expensive models available on the market. Proof of that is that this power supply features passive PFC, which is a cheaper solution compared to active PFC.
The main drawback in using passive PFC is a lower efficiency compared to active PFC units: 78% against 80%+. This 78% efficiency, however, still puts this power supply way above “generic” power supplies with no PFC at all. A secondary drawback comes from the power supply weight: since passive PFC is based on a transformer, this power supply is heavier than units based on active PFC.
Unfortunately we don’t have a load tester yet, so we can’t say if this unit can really deliver its rated 550 W or not. Also because of that we can’t say anything about the unusual design used on its +12 V output.
This power supply features two +12V rails but in our opinion these two rails are not well distributed, since the second rail (+12V2) is used only by the ATX12V output. The first rail (+12V1) is, in our opinion, overloaded, since everything else (motherboard, video cards, hard disk drives, etc) is connected to it. The main problem of this configuration is that the over current protection (OCP) can kick in even though you haven’t reached this power supply’s maximum power. We think GlacialPower should have moved some of the outputs to the second rail (+12V2) or even used a three-rail design, putting the main video card power connector on the third rail.
We also think that the number of SATA connectors available on this power supply – only two – is simply not enough for today’s demands. It should have at least four.
As for the temperature, on the box and on GlacialPower's website the manufacturer says this unit was labeled at 45º C. Why this is important? The higher the internal power supply temperature, the lower power it can deliver. Usually when no temperature is mentioned, the manufacturer assumes 25º C. You will never get 25º C inside a power supply; typical real-world values are found between 35º C and 40º C. So a power supply labeled at 25º C may not deliver its labeled power when running in the real world.
Is this a good product? Well, if you are trying to save some money and you are not building a high-end system it is an interesting choice – especially when you think that 550 W power supplies from well-known brands cost a lot more. But we think if you are building a SLI or Crossfire system or even a system using a very high-end single card there are options on the market that provide a better cost/benefit ratio, especially OCZ StealthXstream 600 W, even though this product from OCZ costs a little bit more.
