Introduction

In May, Antec sent us the 850W version of their Signature series, which delivered quite an impressive performance. They now have a smaller 650W model, and we wanted to test it and see how it compares to its "big brother". The appearance and feature set of the two models are similar, with the only difference being the rated wattage and price. We'll also discuss how it compares with competing power supplies from other manufacturers.


With the Signature series, Antec delivered with the first PWM-controlled fan, which they of course immediately patented. Antec wants to use this control unit to allow for better tuning of fan speeds and promises up to 50% quieter performance -- though we have to ask, 50% compared to what? Enermax utilizes a similar technology in their new Pro82+ and Modu82+ power supplies, which resulted in very low acoustic noise when we tested them. In addition, Antec already runs these power supplies with VRMs to generate the 3.3V and 5V rails instead of the old-fashioned transformer approach. We have seen Silverstone and Enermax follow that trend, and soon Seasonic will join them, as this technology brings a lot of benefits. For example, you get not only short transient response times but also better efficiency from the generated voltages.


The specifications show a minimum load on all rails, which is a no-load operation feature. This means that the PSU can run without any component attached to it. Normally power supplies have problems if you run it without a load attached, i.e. if you were to only connect a hard drive. The 3.3V and 5V rails both deliver up to 24A for a combined power of 140W, which is more than sufficient. There are three 12V rails, with 22A for the first two rails and 25A for 12V3. All of these rails have a combined power of 634W plus the -12V and standby 5V rails.

Packaging and Appearance
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  • swaaye - Tuesday, October 28, 2008 - link

    With regards to 80mm vs 120mm, I think that the best PSUs often have 80mm fans seems to say something.

    In the PSUs I've opened that have 120s, they are obviously restricted on component height inside. PSUs with 80mm fans are also designed around the air flowing from front to back, with heatsink cooling appropriately in-lined with the flow. A bottom 120mm isn't going to make airflow remotely as orderly.

    I have used a mix of 80mm and 120mm units. Some 80mm units are as quiet as the quietest 120mm units, and some 120mm units are much louder than the 80mm units. Neither has an innate advantage with noise.
    Reply
  • ducnow - Friday, October 03, 2008 - link

    I would sooner have a small fan with a direct airflow with no restrictions front to back than a bottom 120mm fan under a poorly designed "quite" PSU that has poor airflow.

    The only thing I wish they would have done is made a single rail edition with more modular cables.

    Another thing that sucks is that we just had a PSU make over in the last 4 years with the Nvidia cards using 8 pin on the GPU and higher end boards using a 6pin. I wonder if these will still be the standard when the new core i7 boards & the new Nvidia cards come out?
    Reply
  • DTL - Thursday, October 02, 2008 - link

    Why the Ambient Temperature only 25°C ? If you are not A big white bear lives near the North Pole.Your case always 40+°C and even 50°C for my case !!! Will there any testing condition down to the earth ? Reply
  • strikeback03 - Friday, October 03, 2008 - link

    Then I'd say the airflow in your case could use improvement. No reason for internal temps to be over 40*C. My Centurion 5 internals are around 32-35*C (P965, E6600, Tuniq, 4GB, 2 320GB HDD, 7600GT) Reply
  • TravisChen - Saturday, October 04, 2008 - link

    We have to set the standard near the worst case, not the optimal case. Quiet a few users have their CPU fan pumping hot air directly into the PSU so even your GFX and HDD are cool your PSU is not. Reply
  • strikeback03 - Monday, October 06, 2008 - link

    My measurements were with a thermocouple inserted through a hole in the case, not on-board sensors. Reply
  • HOOfan 1 - Thursday, October 02, 2008 - link

    Did you miss this?

    "we will keep the ambient temperature at 50°C in the stress test. "
    Reply
  • HOOfan 1 - Thursday, October 02, 2008 - link

    you consider 14.5mV a bit high? When the spec is all the way up at 50mV for 3.3V and 5V. 12V rails is "a bit lower" again, are you kidding? below 9mV when the spec is all the way up to 120mV.

    Really, are you trying your best to seem impartial since the Antec Signature ad is the top banner ad on this site?
    Reply
  • bob4432 - Thursday, October 02, 2008 - link

    would you guys compare this to the ea-650 to see what the extra ~$150 gets us? Reply
  • 7Enigma - Thursday, October 02, 2008 - link

    That's what I'd like to see as well. There is a DRASTIC difference in price between these 2 models, and my guess is the price does not fit the increase in quality/performance. But I need to know for sure. :) Reply

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