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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.

Transient Response Tests

Advanced Transient Response Tests

For details on our transient response testing, please click here.

Ιn these tests, we monitor the Enigma 850's response in several scenarios. First, a transient load (10A at +12V, 5A at 5V, 5A at 3.3V, and 0.5A at 5VSB) is applied for 200ms as the PSU works at 20 percent load. In the second scenario, it's hit by the same transient load while operating at 50 percent load.

In the next sets of tests, we increase the transient load on the major rails with a new configuration: 15A at +12V, 6A at 5V, 6A at 3.3V, and 0.5A at 5VSB. We also increase the load-changing repetition rate from 5 Hz (200ms) to 50 Hz (20ms). Again, this runs with the PSU operating at 20 and 50 percent load.

The last tests are even tougher. Although we keep the same loads, the load-changing repetition rate rises to 1 kHz (1ms).

In all of the tests, we use an oscilloscope to measure the voltage drops caused by the transient load. The voltages should remain within the ATX specification's regulation limits.

These tests are crucial because they simulate the transient loads a PSU is likely to handle (such as booting a RAID array or an instant 100 percent load of CPU/GPUs). We call these "Advanced Transient Response Tests," and they are designed to be very tough to master, especially for a PSU with a capacity of less than 500W.  

Advanced Transient Response at 20 Percent – 200ms

VoltageBeforeAfterChangePass/Fail
12V12.094V11.913V1.50%Pass
5V5.071V4.972V1.95%Pass
3.3V3.330V3.207V3.69%Pass
5VSB4.992V4.950V0.84%Pass

Advanced Transient Response at 20 Percent – 20ms

VoltageBeforeAfterChangePass/Fail
12V12.096V11.815V2.32%Pass
5V5.071V4.963V2.13%Pass
3.3V3.331V3.171V4.80%Pass
5VSB4.991V4.944V0.94%Pass

Advanced Transient Response at 20 Percent – 1ms

VoltageBeforeAfterChangePass/Fail
12V12.098V11.935V1.35%Pass
5V5.072V4.965V2.11%Pass
3.3V3.331V3.186V4.35%Pass
5VSB4.990V4.933V1.14%Pass

Advanced Transient Response at 50 Percent – 200ms

VoltageBeforeAfterChangePass/Fail
12V12.051V11.955V0.80%Pass
5V5.039V4.941V1.94%Pass
3.3V3.307V3.187V3.63%Pass
5VSB4.949V4.904V0.91%Pass

Advanced Transient Response at 50 Percent – 20ms

VoltageBeforeAfterChangePass/Fail
12V12.052V11.907V1.20%Pass
5V5.040V4.919V2.40%Pass
3.3V3.308V3.166V4.29%Pass
5VSB4.949V4.900V0.99%Pass

Advanced Transient Response at 50 Percent – 1ms

VoltageBeforeAfterChangePass/Fail
12V12.054V11.911V1.19%Pass
5V5.040V4.932V2.14%Pass
3.3V3.308V3.149V4.81%Pass
5VSB4.947V4.883V1.29%Pass
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The Enigma 850W successfully passes all of our transient response tests, though we'd like to see lower deviations on the 3.3V rail.

Here are the oscilloscope screenshots we took during Advanced Transient Response Testing:

Transient Response At 20 Percent Load – 200ms

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Transient Response At 20 Percent Load – 20ms

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Transient Response At 20 Percent Load – 1ms

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Transient Response At 50 Percent Load – 200ms

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Transient Response At 50 Percent Load – 20ms

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Transient Response At 50 Percent Load – 1ms

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Turn-On Transient Tests

In the next set of tests, we measured the response of the PSU in simpler transient load scenarios—during its power-on phase.

For the first measurement, we turned the Enigma 850 off, dialed in the maximum current its 5VSB rail could output, and switched the PSU back on. In the second test, we dialed the maximum load the +12V could handle and started the 850W supply while it was in standby mode. In the last test, while the PSU was completely switched off, we dialed the maximum load the +12V rail could handle before switching it back on from the loader and restoring power. The ATX specification states that recorded spikes on all rails should not exceed 10 percent of their nominal values (+10 percent for 12V is 13.2V, and 5.5 V for 5V). 

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Nothing our of the ordinary here.

  • 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....
    Reply
  • gdmaclew
    All I want to know is...Tier 1, Tier 2, Tier 3 or Tier 4?
    Reply
  • 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..
    Reply
  • 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.
    Reply
  • 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.
    Reply
  • 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.
    Reply
  • 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.
    Reply
  • 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.
    Reply
  • Robert Cook
    If nothing else it is more competition, and a pretty promising start at that.
    A solid review.
    <Rant>
    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.
    </Rant>
    Reply
  • 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.)
    Reply