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Rosewill Photon-1200 PSU Review

Today, we evaluate Rosewill's Photon-1200, manufactured by Sirfa, featuring fully modular cabling, Gold-rated efficiency and a high watt-per-dollar ratio.

Pros, Cons And Final Verdict

Rosewill is doing an outstanding job expanding its portfolio with all kinds of PSUs, covering the needs and demands of all categories, from the mainstream to the ultra-high-end. In the case of the 1.2kW Photon, the company's aim was to offer a powerful and efficient unit with some high-end features at a budget price. Admittedly, the Photon-1200 is one of the most affordable 1.2kW PSUs with an 80 PLUS Gold rating. However, if you spend just a bit more, you can get a much better-performing unit with higher efficiency, lower ripple and lower noise output from Rosewill or another vendor.

For many users, a PSU's acoustics can become really annoying, and in this case, they have every right to complain. The Photon-1200 is among the noisiest supplies we have ever tested. Rosewill could easily make it quieter by using a more relaxed fan profile. The existing one was most likely chosen to ensure the unit's cooling would be optimal under all conditions, as Rosewill's top concern was increasing the PSU's reliability to support a lengthy five-year warranty. The fan almost certainly has a greater thermal load to handle compared with other, more efficient PSUs in this category. But under lower loads, the company could make it spin slower, suppressing its noise levels.

If you're looking for a powerful PSU to go in a system that will be isolated (so that its noise won't be an issue), the Photon-1200 could save you some money, so long as you keep it running inside of a cool chassis. Unfortunately, the supply's price advantage isn't very big compared with other high-performance PSUs in this category, so it's equally tempting to simply buy something else.

Besides its noisy operation, the most significant problem with the Photon-1200 is bad ripple suppression at increased ambient temperatures. On the other hand, its strong points are quality Japanese capacitors, a fully modular cabling design and the ball-bearing fan that should last for quite a long time.

If the price came in under $150, we believe this could be an appealing option for folks wanting an affordable, fully-featured 1.2kW PSU. With its current price tag of $170, however, the unit is unlikely to claim a big market share in this category where other companies, including Corsair, Seasonic, EVGA, Super Flower and FSP offer better alternatives.

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Aris Mpitziopoulos is a Contributing Editor for Tom's Hardware, covering Power Supplies.
Follow us on Twitter @tomshardware, on Facebook and on Google+.

  • MasterMace
    Sirfa has produced too many poor units in the past to get any leeway or benefit of the doubt. It failed 80 Plus Gold in the hotbox at 100% load.
    Reply
  • boller
    I have a good perspective on that ripple thing: just finished repairs of a PC power supply and when I was measuring ripple I found it was out of whack (300 mV pp). After some investigation I found out that measuring ripple is a tricky thing. Tom's description on how they do it is very incomplete. Eevblog guy spent an entire episode on ripple. In my case I had to do this: limit oscilloscope bandwidth 20 MHz, instead of the grounding clip use that spring attachment and measure loaded PSU at the last cap before leads. Ripple went down from 300 to 48 mV pp.
    Reply
  • Aris_Mp
    First of all you don't just hook a scope on a PSU's output and measure ripple else you will catch huge spikes, like in your case, which will totally alter the measured result.

    Secondly most users aren't interested on how I do things (and even if I elaborated on all the procedures I follow only a fraction of them would understand them) but about the final result. For me the most important is to explain what ripple is and how it can affect the components of a system.

    Thirdly. You don't have to watch Dave to see how ripple is measured properly. You can check on the ATX spec which includes the ripple measurement procedure. I follow all guidelines of the ATX spec so if you need to see how I measure ripple or load regulation just take a look at them. In any case the following scheme will show you how to measure ripple on a PSU.

    Reply
  • boller
    No need to be defensive, I was just pointing out that your _description_ is incomplete, not that you do it wrong. Although it would be nice for you to place a note over there saying that actual procedure involves some additional caps and an honest to god differential probe (!)
    Reply
  • Aris_Mp
    I just replied to your concerns. No need to think that I am defensive because clearly this is not the case with me.

    I already stated that I don't mention how I measure ripple since among others all of us reviewers have to follow the ATX spec procedure. There is no point in repeating the whole ATX spec from the moment that anyone can download and read this spec with a simple google search.

    Besides these two caps (which are already pre-installed on the fixtures that most of us reviewers have. There also present on loaders like the Sunmoon ones) and the good quality probes you also need to isolate all external noise that can pass from the PSU's EMI filter. In other words you need to provide "clean" power to the PSU. Personally I do this with a Chroma AC source and in the near future I plan to get a online UPS with some extra circuits for EMI/noise protection which will feed the AC source (so I will have two layers of protection). In order to check if your line is clean firstly take some readings on the major rails (+12V, 5V and 3.3V) with the PSU in standby. If you see increased ripple (normally it should be close to zero mV) then your scope picks up noise or the PSU isn't properly isolated from the rest devices on your home/lab.
    Reply
  • CTurbo
    It's not a bad unit, but it's not competitive at all. It's more expensive than an EVGA G2 1300w Gold and and Rosewill Capstone 1200w Gold, and almost as much as an EVGA P2 1200w. Yikes!
    Reply
  • Mac266
    Shame it performed badly, a cheap high rated supply could stir the market up nicely!

    It's not a bad unit, but it's not competitive at all. It's more expensive than an EVGA G2 1300w Gold and and Rosewill Capstone 1200w Gold, and almost as much as an EVGA P2 1200w. Yikes!

    CTurbo! How ya been mate?
    Reply