Riotoro Enigma 850W PSU Review

Riotoro is a newly founded company that's currently involved in the PSU, chassis, cooling, and gaming peripheral markets. It only has two PSU lines with three total members, and today we're looking at the Enigma 850W, its flagship offering.

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Load Regulation, Hold-Up Time, And Inrush Current

To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units. 

Primary Rails And 5VSB Load Regulation

Load Regulation testing is detailed here.

Hold-Up Time

Our hold-up time tests are described in detail here.

The registered hold-up time we measured is low. The only good news is that Great Wall tuned the power-good signal to drop before the rails go out of spec. Still, we'd like to see the delay closer to 1ms, as the ATX spec requires.

Inrush Current

For details on our inrush current testing, please click here.

The inrush current is low with 115V input, and at normal levels with 230V.

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the Enigma 850's efficiency. The applied load equals (approximately) 10 to 110 percent of the PSU's maximum load in increments of 10 percentage points.

We conducted two additional tests. During the first, we stressed the two minor rails (5V and 3.3V) with a high load, while the load at +12V was only 0.1A. This test reveals whether a PSU is Haswell-ready or not. In the second test, we determined the maximum load the +12V rail could handle with minimal load on the minor rails.

Swipe to scroll horizontally
Test #12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan SpeedFan NoiseTemps (In/Out)PF/AC Volts
15.221A1.965A1.975A0.996A84.75386.136%825 RPM25.9 dB(A)38.56°C0.955
211.482A2.950A2.971A1.198A169.60490.210%870 RPM27.0 dB(A)39.39°C0.960
318.125A3.456A3.489A1.405A254.86291.060%905 RPM29.4 dB(A)39.47°C0.972
424.759A3.954A3.979A1.611A339.68990.994%1020 RPM31.8 dB(A)39.88°C0.979
531.067A4.967A4.988A1.815A424.68090.553%1140 RPM35.3 dB(A)41.70°C0.984
637.388A5.967A6.001A2.025A509.58689.827%1210 RPM37.6 dB(A)41.91°C0.987
743.724A6.987A7.020A2.235A594.56888.966%1295 RPM39.8 dB(A)42.78°C0.990
850.076A8.003A8.049A2.446A679.45987.983%1430 RPM41.9 dB(A)44.19°C0.992
956.884A8.516A8.584A2.451A764.50487.075%1575 RPM43.7 dB(A)44.59°C0.993
1063.437A9.045A9.093A3.084A849.30185.903%1680 RPM45.2 dB(A)45.65°C0.994
1170.620A9.056A9.106A3.089A934.19284.809%1680 RPM45.2 dB(A)46.44°C0.995
CL10.100A16.027A16.004A0.004A133.64483.910%1095 RPM33.5 dB(A)42.81°C0.960
CL270.791A1.003A1.003A1.002A860.74486.253%1680 RPM45.2 dB(A)46.51°C0.994

Load regulation at +12V is tight enough. On the minor rails it falls within 2.5%, so we consider that satisfactory. The 5VSB rail in these tests suffers a greater deviation of around 3.7%, but because it's still within the ATX specification, we aren't concerned.

The Enigma's fan profile is quite relaxed up to the 40% load test, and output noise exceeds 40 dB(A) only at higher loads with 80% of the PSU's maximum-rated capacity. Although the max temperature for full power delivery is restricted at 40°C, Great Wall still tuned the fan profile for higher operational temperatures. This is a good thing, of course.

Our results show the Enigma easily meeting the 80 PLUS Gold requirements with 20% and 50% load. However, it falls short during the full-load test where it should achieve at least 87% efficiency. As we already know, though, 80 PLUS conducts its tests at low ambient temperatures, where efficiency is higher.

Aris Mpitziopoulos
Contributing Editor

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

  • Pompompaihn
    Enigma is a HORRIBLE name for the one part in your computer you want to always work exactly as specified and never outside of those specs....
  • gdmaclew
    All I want to know is...Tier 1, Tier 2, Tier 3 or Tier 4?
  • zthomas
    850 will power a normal system.. but thinking VR or a second video card.. 850 ain't enough.. I just upgraded from a 700 to a 1200.. why go small, go larger.. you run a 900 series.. you want a punch.. not a lag..
  • maxwellmelon
    A mov can be a blessing and a curse. When the MOV eventually fails it offers no protection (and there is no indicator on it to indicate failure) then after awhile it will form into a short at which point the psu will fail to work due to a short on the incoming mains. so your MOV will can extend the life by protecting the psu. but in the end it will be the end of the psu. In a lot of ways it is still better to get a good surge protector with MOV protection inside of it because they actually have an indicator to let you know the MOV has failed and you can actually replace the surge protector..If the MOV has failed in the psu you will never know and even if you did know the whole PSU has to be replaced. a good surge protector is still cheaper to replace then the psu.
  • anbello262
    19366477 said:
    850 will power a normal system.. but thinking VR or a second video card.. 850 ain't enough.. I just upgraded from a 700 to a 1200.. why go small, go larger.. you run a 900 series.. you want a punch.. not a lag..

    I actually don't agree with you at all. 850w is enough for almost any system with even 1080 SLI, and VR doesn't actually require more power by itself (only requires power by high utilization of your system).
    So for almost anyone, 650w is more than enough even for high end systems, and if you want to SLI high end cards, then 850W is advisable.
    More than that is overkill in almost all cases, in my (somewhat informed) opinion.

    Having a good quality PSU is a lot more important than having more than 850W. And quality PSUs with more power tend to be a lot more expensive than a very good 850w one, from my experience.
  • Aris_Mp
    you are right about the MOV, however personally I prefer a PSU featuring a MOV along with a UPS and a surge arrester combination. Moreover, for users that don't use surge arresters etc a MOV can save their systems besides the PSU and this is why it must be used always.
  • jonnyguru
    19365339 said:
    All I want to know is...Tier 1, Tier 2, Tier 3 or Tier 4?

    If that's not a joke, then you sir do not need to be here... let alone building PCs.
  • anbello262
    19369895 said:
    19365339 said:
    All I want to know is...Tier 1, Tier 2, Tier 3 or Tier 4?

    If that's not a joke, then you sir do not need to be here... let alone building PCs.

    Actually, having the PSUs ordered in quality tiers is a very handy way to recommend PSUs, and therefore, for the people who are not so technically proficient with the electronics inside a PSU and specific meanings of the tests, knowing if this is a "Great, good or garbage" PSU is the only important part.

    Yes, there is more information to be had by reading the whole review, but only for those who understand it (which is by no means necessary, in order to be a very good system builder). Having a qualified person tell you "this is a safe and recommended unit for system builders / this is good enough for the price / don't buy this!" is extremely useful for the whole community.
  • Robert Cook
    If nothing else it is more competition, and a pretty promising start at that.
    A solid review.
    Now on other news, PLEASE stop those damn auto play videos embedded in articles! My main system might be fine with them, but my laptop is from 2009, and it was not high spec even then. These videos are a major drain, and now there are ads before hand which means I cannot even hit the X option until the ad has played. (So I am loading free ad revenue for you at the cost of my precious little RAM.)

    Annoying clickbait is one thing, I can scroll past it, but these auto play ads/videos follow me down the page... :(

    I have been a member here for over two years and I am by no means going to stop, but I would like to be able to read articles (especially well done articles on this site) with out having great difficulty even scrolling down a page.
  • Robert Cook
    Also I do not even use adblock so you are already getting ad revenue. (I respect your right to advertise, but force playing a video and then adding ads seems a bit over blown.)