Few things have influenced product politics as much as 80 Plus Gold. Seasonic was the first manufacturer to list power supplies on its homepage meeting the EPRI (Electrical Power Research Institute) guidelines, and they presented their first certified models at CeBIT 2009. With the recently launched X-series, Seasonic aims to prove the marketability of 80 Plus Gold PSUs. We have the 750W model for review today, so let's see how it measures up. Is it a great new PSU, or is 80 Plus Gold simply a new way to increase prices?

Beyond the remarkable efficiency and high-quality technology, the power supply contains a fully modular cable system and makes a good impression with its simple elegance. The X-Series also includes "hybrid silent fan control", which regulates the three speed settings of the fan. The power supply runs completely silent up to 20% load, at which point the fan begins to rotate slowly; at higher loads fan speed increases again to enable sufficient cooling. Seasonic uses a PWM fan to allow graceful ramping up of fan speeds, which we will cover later in this review. Beyond the various certifications and features, this ATX 2.3 power supply offers a 5-year manufacturer warranty and uses active PFC to allow its use on all the major power grid standards.

Enermax delivered good results in our previous test with the latest Pro87+/Modu87+ series, and it will likely be Seasonic's main competition. Of particular note is that the noise levels of the Pro87+ and Modu87+ are extremely quiet throughout the load range. Enermax also delivers products catering to the midrange 500W market, but we will have to wait until summer for Seasonic's answer. When the other models are ready, Seasonic let us know that they will have PSUs rated below 500W for those that don't run a high-power system. We should also see additional manufacturers soon with their own 80 Plus Gold offerings, so it remains to be seen who will have the best product. Apart from the marketing hype, we'll need to see new features in order to surpass the competition.

The X-Series has an MSRP of $200 for the 750W unit we're reviewing, but you can find it online starting at $180. So let's see if this expensive power supply is worth the money and if Seasonic can achieve new efficiency levels. We will also look at the construction, voltage output, and the unusual topology; high efficiency isn't the only point of interest with the X-Series.

X750 - Product Contents and Overview
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  • vol7ron - Tuesday, April 13, 2010 - link

    Nice Martin, I've been looking at upgrading my PSU (550W ultra) and I only like buying the modular connectors. $200 still seems kind of high, but almost in the reasonable range. I'd like it to be $150 :)

    Another thing I might be shopping around for is a new UPS, have you guys reviewed any of those recently?
  • HOOfan 1 - Wednesday, April 14, 2010 - link

    There is a 650W version. Selling for $160 at newegg now
  • jeffbui - Wednesday, April 14, 2010 - link

    $138 at ewiz/superbiiz for the 650w version. I couldn't be happier with it.
  • vol7ron - Wednesday, April 14, 2010 - link

    I like the plan for the future though, especially with power supplies since they last long.

    My guess was that the next upgrade would be 750W or higher, the real goal was to have an 800W PSU and UPS. My machine probably only currently uses 350W, but I like to have headroom, especially since I keep adding HDs and will probably take advantage of more PCI slots in the future.
  • Souka - Wednesday, April 14, 2010 - link

    HX650 or HX750 (both are modular)

    HX650 is $120 at NewEgg, I have it... quiet and works well. Reviews show it to be 80+ Silver. but Corsair chose to be Bronze as their own testing (under very hot conditions) didn't qualify for Silver... Kudos to Corsair.
  • Souka - Wednesday, April 14, 2010 - link

    Sorry..my bad. Corsair PSU is Silver...almost Gold.

    One important thing about the HX650 and HX750 PSU is that they're just shy of 90% effecient at a VERY wide range of loading.

    True, the Seasonic unit does do better at PEAK efficiency (if using 220v) by a few %, but if you're actually going to use a 750W PSU at any other load than this, the Corsair will save you $$ upfront and in the long run with lower power bills.

    My $.02
  • HOOfan 1 - Wednesday, April 14, 2010 - link

    HX650 is bronze...nothing more than bronze

    HX750 is silver and was originally awarded Gold by 80plus.
  • Franson - Wednesday, April 14, 2010 - link

    Are you a bot or something? Take your stupid Corsair fanboyism and shove it....!!
  • Souka - Thursday, April 15, 2010 - link

    Wow... nice post...
  • piroroadkill - Thursday, April 15, 2010 - link

    The HX650 IS a Seasonic design, and I think, by looking at it, the HX750 is a Channel Well design. Regardless, Seasonic was also the OEM for the HX520 and HX620. Seasonic make damn fine power supplies.

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