Antec Signature 650W Power Supply

Conclusion

We thought the 850W version of the Antec Signature series was very good, so we wanted to see if the smaller model could deliver a similar performance. We weren't disappointed with what we saw today. This kind of topology of course only works with an 80mm fan at the back or the front of the PSU, and Antec made a good choice in including a PWM-controlled fan. Even though we heard ticking noises from the fan during lower rotations, it wasn't very audible and we would rate it as being very quiet.

The selection of cables and connectors is okay for a 650W power supply, but we would have liked an additional PCI-Express connector. With only two connectors, users can still power up every available single graphics card or even a moderate SLI/CrossFire setup -- provided that each card only needs a single 6-pin connector. It is not possible to run any higher graphics configurations, unless you use Molex to PCI-E adapters (which we don't usually recommend). The cable lengths are good, and each of the peripheral connectors can reach up to 80cm (32 inches). The ATX and PEG connectors have a length of 50cm (20 inches) which is normal and should not cause problems in most cases.

The build quality is exceptional and the choice of components very good. We found Nippon Chemi-Con and Rubycon caps utilized throughout the PCB. All the components are attached and aligned well, and the construction provides for good airflow. The choice of two VRMs for the 3.3V and 5V rails is good and we welcome this technology as a step that moves the industry forward.

Looking at performance, we saw an average regulation of up to 2.5-3%, which is decent. Another good quality is that the three 12V rails are always regulated close to each other and differ only by a few millivolts. The efficiency reaches 87% at medium load with a high input voltage of 230VAC, and the overall efficiency stays above 85% (with 230VAC) over a very large range of loading. Even with lower input voltages, the efficiency throughout the test is generally above 80%. There was little ripple on the rails, except for the 5V rail which developed fluctuations up to 14.5mV -- still well within specs. At the loads that most users are likely to run, the power supply stay quiet and was almost inaudible with a noise level of only 17dB(A). After 50% load, however, this increases to a rather loud 30dB(A). We definitely recommend users try to avoid running this power supply at maximum load for this reason; if you keep it under 500W of load the performance characteristics are much better. This paired with a normal room-temperature environment will help to reduce the acoustic levels to a minimum.

Average prices for this unit in the U.S. market are around $180-$200 plus shipping. In Europe the prices start at €140 including tax. The street price is fortunately already lower than the $249 MSRP from Antec. The question is, is that cheap enough? Performance and features on tap are better than most of the other power supplies in this range, but it's difficult to say that you are getting $50 more value than, for example, the Hiper HPU-5B680.