Cold Test Results

For the testing of PSUs we are using high precision electronic loads with a maximum power draw of 2700 Watts, a Rigol DS5042M 40 MHz oscilloscope, an Extech 380803 power analyzer, two high precision UNI-T UT-325 digital thermometers, an Extech HD600 SPL meter, a self-designed hotbox and various other bits and parts. For a thorough explanation of our testing methodology and more details on our equipment, please refer to our How We Test PSUs - 2014 Pipeline post.

Even though only barely, the Rosewill Photon 1050W does honor its 80Plus Gold certification badge. The energy conversion efficiency reaches 92.2% at 50% load, with an average of 90.7% within the nominal load range (20% to 100% of the unit's capacity). At low loads the unit performs very well, maintaining an efficiency of 85.6% at 10% load and 78.5% at just 5% load.

The thermal control circuitry of the Rosewill Photon 1050W seems to favor acoustics over thermal performance, allowing the internal temperatures of the unit to get a little higher so that the fan will not be as noisy. At room temperature, the Photon 1050W is almost entirely inaudible up to 50% load, which is an output of over 500W. After that point however, the fan will start increasing its speed sharply and becomes clearly noticeable.

The Rosewill Photon 1050W PSU Hot Test Results


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  • DanNeely - Tuesday, March 24, 2015 - link

    Yup. And while I know loaned/donated hardware is the default for most reviews; in a roundup review, spending $30-60 for a single no-name model to show what spending a little more for a brand name model gives should be an acceptable use of editorial dollars. Two cheap models might be worth it as well; one obvious garbage box to be sacrificed on the alter of magic smoke, and a second that while expected to survive is a few steps down on the performance scale (eg bare 80plus). I wonder if you might be able to fiangle the latter out of one of the OEMs: "I want a baseline model to demonstrate why your 80+ gold model is worth the extra $20." Reply
  • chlamchowder - Wednesday, March 25, 2015 - link

    If I may add one more thing, I have never once looked at a 1000W power supply and said "this unit performs well, so this brand's 400-600W units must be good too".

    When I went shopping for a PSU, I went for a $40 500W model with a plain 80+ rating because there were practically no reviews of sub-$100 400-600W units (and I didn't want a $20 no-name model that might have 45% efficiency). But if reviews showed that spending $100 gave a big improvement over lower priced units, I might have decided differently.
  • DanNeely - Tuesday, March 24, 2015 - link

    The other half is that high efficiency PSUs only pay for themselves under largish 24/7 loads at typical US power prices. I played around with the numbers recently for my new build:For a 24/7 load (distributed computing), $0.12/kwh for electricity, modular designs only, and wanting ~200W headroom to keep the PSU fan from adding to the system noise; and over 6 years a 91% platinum PSU only broke even over an 88% gold unit if I ran SLI/xFire for about half the time. In a pure single GPU config the gold model barely broke even vs a cheaper silver model. I ended up going with the platinum model because I expect the 5k monitor I'm planning on buying in the next 12-24 months almost certainly will require SLI/xFire for a few years; combined with a housing situation where my landlord is responsible for the heating bill while air conditioning is on me tipping the scale.

    If your PC spends most of its day off/idle a high efficiency PSU isn't going to give much of a return except possibly at very high electricity rates. If an OEM ever makes one, a small 80+ titanium unit might be worthwhile for mainstream users just due to the large boost it requires at a 10% load.
  • JeffFlanagan - Tuesday, March 24, 2015 - link

    Good point. Power requirements for PCs with massive storage have also come down quite a bit now that 3 2TB drives can be replaced with a single 6TB drive. Reply
  • bigboxes - Tuesday, March 24, 2015 - link

    I have 8 hard drives (1 SDD for the OS) in my file server. If they increase the size I'll just get 8 6TB drives. Right now I'm slowly migrating to 4TB models (up from 1.5TB and 2TB models). Hard drives don't consume a lot of energy regardless. Reply
  • Gigaplex - Tuesday, March 24, 2015 - link

    My home server has 5 hard drives (4x 3TB array plus the OS drive) and i'm using a 450W PSU. The system idles at 60W measured at the wall. It hits about 75W when the array is maxing out the gigabit network connection. The only time you really need to worry about power requirements for "massive storage" is during boot, but if you stagger the spin-up then it's not a problem. Not that I've had to bother with my current system. Reply
  • romrunning - Tuesday, March 24, 2015 - link

    "The high ambient temperatures have a significant impact on the electrical performance of the Photon 1050W, reducing its energy conversion efficiency by an average of 2%. The drop is higher as the load increases, reaching a massive 3.7% drop with a load of 1050W."

    C'mon now, an increase from 2% to 3.7% is NOT a "massive" difference.
  • SirGCal - Tuesday, March 24, 2015 - link

    You wouldn't be saying that if it was the APR % difference in your mortgage for example... If you were at 2% and they raised you to 3.7%, you'd @#$% the bed. Everything is perspective. Reply
  • romrunning - Tuesday, March 24, 2015 - link

    C'mon now, don't conflate two items that are completely different. Changes in a mortgage APR don't equally equate into slight changes in a power supply's energy conversion efficiency.

    If two power supplies were being compared and one was 3.7% while the other was 5.0%, would you still describe the 3.7% variance as "massive"? How would you describe the 5.0% variance?

    E.Fyll did a good job with his review; I just thought the word "massive" was a bit hyperbolic in the context used.
  • E.Fyll - Tuesday, March 24, 2015 - link

    Actually, it is an 85% increase over the average efficiency drop. That, alongside the fact that everything above 1-1.5% for that particular test is very high, is pretty much massive. Reply

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