Conclusion

Since CES, the Signature series was highly anticipated and we have had the chance to take an early look at the upcoming series. We expected much from this unit and we can say the Signature delivered. The packaging gives an understated appearance to the product, which hints at the lack of need for flashy gimmicks and hype. Rather than broken promises, Antec delivers a top-of-the-line product that doesn't need many words.

The build quality was very good, starting with the housing of the unit. After looking inside, we found one of the cleanest builds possible that is further enhanced by the low height of the components. As the Signature comes with two PCBs sandwiched together there is enough space to build the tidy layout we saw today. The use of high quality components such as the Rubycon and Nippon Chemi-Con capacitors enhances the clean design.

There are many connectors already fixed to the power supply, and users have four more jacks on disposal for additional cable harnesses if needed. All of the connectors have a minimum length of 20"/50cm, which is something of a basic standard today, though not a bad standard. On each peripheral harness are three attached connectors and the user has the choice between one fixed SATA and Molex harness and two additional cable harnesses. For users with multi-GPU setups Antec delivers two additional 6-pin PEG connectors.

Looking at performance, we saw voltage drops on the lower voltage rails as well as on the 12V rails. All of the rails perform well within specs but a drop of up to 5% is not small. As for the quality of the output, we measured a very small ripple of up to 26mV on one of the 12V rails.

Buyers of the Signature series can be happy with efficient work, as this unit achieved up to 87% efficiency. Even with lower input voltages, the unit manages up to 85% with 120VAC and up to 83% with 90VAC. These results are some of the best this year, and if the 650W version performs this well it will be a very good competitor to other offerings. That said, the 850W unit should not be used (i.e. it's overkill) with PCs that require less than 150W of power most of the time, as the efficiency is not good enough below this point. This PSU works best with a minimum of 400W power draw.

The acoustic noise was very low up to a load of 600W. Reaching that load with such a low noise was, until now, only possible from a 1000W+ unit. Users might want to take care that the load does not exceed 600W as then the fan will start spinning much faster and create a very noisy environment. The fan turns at only 700RPM at minimal load, and even when it starts spinning faster it remains quiet. Only from 600W onwards is noise a concern, where the PSU can generate up to 40dB(A) acoustic noise.

Antec states an MSRP of $249 for the 650W version and $299 for the 850W version. Both of the prices are quite high as there are 850W power supplies for much less than that, but the price will most likely drop once availability improves. The Signature series definitely left its mark today with very good performance and high efficiency. Now all we need is a more reasonable online price - it really needs to be under $200 and under $150 for the 650W model - and we'll be happy.

Fan Speed and Acoustics
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  • JarredWalton - Wednesday, May 7, 2008 - link

    I have used dozens of Antec cases over the years... I have not yet purchased an Antec PSU separate from a case, however. Then again, Earthwatts might make that a reasonable thing to do these days.
  • strikeback03 - Wednesday, May 7, 2008 - link

    I've used EarthWatts 380 units in a couple of systems for the lab. Seem to do fine, nice and quiet, and prices around $20-30 after rebate at Newegg, works for me.
  • DDG - Wednesday, May 7, 2008 - link

    I recently picked up the Earthwatts 650 unit and I must say I'm impressed so far. It's quiet and has 6 SATA and Molex connectors as well as 2 PCI-Express (1 6-pin and 1 6+2 pin). It replaced a Truepower 550-watt PSU that was 5 years old but still going strong (just too noisy and not energy efficient).

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