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EVGA SuperNOVA 850 P2 Power Supply Review

Transient Response Tests

Advanced Transient Response Tests

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

In these tests, we monitor the response of the PSU in two different scenarios. First, a transient load (10A at +12V, 5A at 5V, 5A at 3.3V and 0.5A at 5VSB) is applied for 200ms while the PSU works at 20 percent load. In the second scenario, the PSU is hit by the same transient load while operating at 50 percent load. In both tests, we used our oscilloscope to measure the voltage drops caused by the 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 tests "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

VoltageBeforeAfterChangePass/Fail
12V12.255V12.213V0.34%Pass
5V5.040V4.952V1.75%Pass
3.3V3.316V3.235V2.44%Pass
5VSB5.066V5.032V0.67%Pass

Advanced Transient Response at 50 Percent

VoltageBeforeAfterChangePass/Fail
12V12.225V12.183V0.34%Pass
5V5.030V4.946V1.67%Pass
3.3V3.307V3.225V2.48%Pass
5VSB5.032V4.991V0.81%Pass
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Super Flower's Leadex platform responds impressively to transient loads. At +12V, the deviations in both tests are minimal; the same applies to the 5VSB rail. Deviations on the 5V rail stay within 2 percent, and the 3.3V rail manages to stay within 2.5 percent (a very good performance for this rail). All in all, the 850 P2 performs well, especially on that crucial +12V rail.

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

Transient Response At 20 Percent Load

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Transient Response At 50 Percent Load

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Turn-On Transient Tests

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

For the first measurement, we turn off the PSU, dial in the maximum current the 5VSB rail can output and switch on the PSU. In the second test, we dial in the maximum load the +12V rail can handle and start the PSU while it's in standby mode. In the last test, while the PSU is completely switched off (we cut off the power or switch off the PSU by flipping its on/off switch), we dial the maximum load the +12V rail can handle before switching on the PSU 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 5.5V for 5V).    

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All slopes ramp up smoothly, and as you can see there are no voltage overshoots or spikes. Great performance overall! 

  • QuangT
    Why can't US use 220v, man so much more efficient.
    Reply
  • JQB45
    Why can't US use 220v, man so much more efficient.
    Tradition... There is nothing (I believe) stopping you from running a 220v circuit. I know we have one 20amp NEMA circuit in this house specificity for the computer room. Its not common to see those in house holds either.
    Reply
  • JQB45
    Tier-1 but on the low end of Tier-1 due to its hold up time.
    Reply
  • cliffro
    17550218 said:
    Tier-1 but on the low end of Tier-1 due to its hold up time.

    Scores a 9.7 on Jonnyguru, but is low end of tier 1 got it.


    I like Tom's in general, been coming here since Tom was actually doing reviews, but I'll take JonnyGuru's(or Oklahoma Wolf) word that this is an awesome PSU, it scored 10 of 10's in all but Value, where a couple of similar quality PSU were a tad cheaper.

    I've got the G2 model(thanks to their review of it) and couldn't be happier with it. Well other than they now have Platinum and Titanium versions and would prefer one of those. But 80+ Gold is still good enough for me.
    Reply
  • powernod
    17550218 said:
    Tier-1 but on the low end of Tier-1 due to its hold up time.

    Scores a 9.7 on Jonnyguru, but is low end of tier 1 got it.


    I like Tom's in general, been coming here since Tom was actually doing reviews, but I'll take JonnyGuru's(or Oklahoma Wolf) word that this is an awesome PSU, it scored 10 of 10's in all but Value, where a couple of similar quality PSU were a tad cheaper.

    I've got the G2 model(thanks to their review of it) and couldn't be happier with it. Well other than they now have Platinum and Titanium versions and would prefer one of those. But 80+ Gold is still good enough for me.


    Well, i think that you don't pay that much attention to Jonnyguru.com, as much as you claim.
    Look here, at Jonny's tier list, and notice what tier is the EVGA's P2 line :
    http://www.jonnyguru.com/forums/showthread.php?t=12947
    Reply
  • dstarr3
    Why can't US use 220v, man so much more efficient.

    The same reason so many regions have different plug types. They all designed these things before anyone had the idea to standardize these things across regions, and by now it's an incredible amount of work to have to redesign the infrastructure of entire countries.
    Reply
  • Adhmuz
    Why can't US use 220v, man so much more efficient.
    "Technology, current at the time of US electrification, locked the US into 110, then 120 volt outlets. Europe's electrification came later, and proceeded in response to advanced technology. The US was too deep into the 110/120 volt infrastructure to upgrade."
    Gotta hand it to the Americans for inventing the concept of the grid and power distribution to the masses, they did it first, and Edison's equipment at the time ran best on 110v so it was the obvious choice. Currently it's at 120v, this was changed in the 50s. Don't forget houses are supplied with 240v, this is what runs our hot water heaters, ovens and air conditioners. Just the old way is still too set in stone to be changed, not to mention 120v is safer for human exposure (a shock from a 120v outlet is much less dangerous than that of a 240v outlet, having experienced the 120v shock I can't imagine how painful a 240v would be)
    Reply
  • 10tacle
    17552491 said:
    Just the old way is still too set in stone to be changed, not to mention 120v is safer for human exposure (a shock from a 120v outlet is much less dangerous than that of a 240v outlet, having experienced the 120v shock I can't imagine how painful a 240v would be)

    Yep...I was popped by a 220v 3-prong washing machine plug wire that arced some two decades ago (when it was still known as a 220v power connection) and it knocked me on my butt. It makes getting hit by 120v (used to be 110v), which I've also experienced more recently, seem like carpet static electricity.

    Reply
  • cliffro
    17552081 said:
    17550218 said:
    Tier-1 but on the low end of Tier-1 due to its hold up time.

    Scores a 9.7 on Jonnyguru, but is low end of tier 1 got it.


    I like Tom's in general, been coming here since Tom was actually doing reviews, but I'll take JonnyGuru's(or Oklahoma Wolf) word that this is an awesome PSU, it scored 10 of 10's in all but Value, where a couple of similar quality PSU were a tad cheaper.

    I've got the G2 model(thanks to their review of it) and couldn't be happier with it. Well other than they now have Platinum and Titanium versions and would prefer one of those. But 80+ Gold is still good enough for me.


    Well, i think that you don't pay that much attention to Jonnyguru.com, as much as you claim.
    Look here, at Jonny's tier list, and notice what tier is the EVGA's P2 line :
    http://www.jonnyguru.com/forums/showthread.php?t=12947

    This is the summary for my EVGA 850 G2 (Tier 2 according to his list, a WIP according to the post)
    Performance
    10
    Functionality
    10
    Value
    10
    Build Quality
    9.5
    Total Score
    9.9

    Summary

    Buy one. Do I really need to say anything else at this point? Once again, EVGA has something awesome here the competition can't seem to touch price wise. Performance? There are better units, yes. Not very many, but they exist. The real story here is how EVGA keeps managing to offer this kind of performance and still be more affordable than nearly everything else out there, and they have pretty much found perhaps the only OEM on Earth capable of doing it for them. It's got to be real nice being EVGA right now.

    The Good:

    outstanding ripple suppression
    excellent voltage regulation
    fully modular
    semi-fanless mode
    nice blacked out cabling
    The Bad:
    nothing at all
    The Mediocre:
    reviewing awesome units is getting dull... where's that gutless wonder in my pile? Second in line? Well, at least I'm guaranteed something interesting in all the wrong ways in a couple weeks...
    It scores a 9.9 of 10, and is somehow a Tier 2 according to that list. I have no clue as to what he is doing with his list on the forums. I cannot explain HOW a unit that scores 9.9 of 10 is anything less than Tier 1. There are some Corsair units that scored perfect 10's that are also listed as Tier 2 on it as well.

    If it's scoring that close to 10, or an actual 10 (his highest score), it's a Tier 1 to me. And I'd never second guess buying one regardless of brand.
    Reply
  • Amdlova
    you guys cry like a baby. i use 227v on the computer no ground. with a multimeter can see about 45v on chassis its nice to touch it. i use a ps3 power supply to drive a 400w car amplifier and the psu barely get warm, no fan only passive cooler. 127v as no good use anymore on non days.
    Reply