Seasonic Prime 850 W Titanium PSU Review

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Protection Features

Check out our PSUs 101 article to learn more about PSU protection features.  

Our protection features evaluation methodology is described in detail here.

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Protection Features
OCP12V: - 5V: 28.1A (140.5%) 3.3V: 27.3A (136.5%) 5VSB: 4.1A (136.7%), 79.86mV Ripple
OPP1178.81W (138.7%)
OTPYes (>130°C secondary heat sink)
SCP12V: Yes 5V: Yes 3.3V: Yes 5VSB: Yes -12V: Yes
PWR_OKProper operation
NLOYes
SIPSurge: MOV Inrush: NTC thermistor & bypass relay

OCP's triggering points are quite high on the minor rails, though this won't create any trouble since load regulation and ripple suppression are kept under control. However, at 5VSB, ripple with 4.1A is higher than the specification allows, while with only 0.1A lower load it's normal again. Seasonic should look into this and fix it. Lastly, the OPP is set really high. Then again, the PSU doesn't have any problems under almost 1.2kW of load (at normal ambient temperatures, at least).

The other protection features operate properly. OTP is notably present and configured at an optimal level, allowing the PSU to run even under 50°C temperatures per the ATX specification's recommendation.

Contributing Editor

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

  • trampus123
    I want one
    Reply
  • Nintendork
    There's no need for CF/SLI anymore, the typical PC + RX480/1080 class gpu barely goes above 300w (even less with APU setups or RX460/1050ti). We need way more 400-500w Titanium PSU's.

    We should have 90% efficiency at 50w load with PSU's in that wattage range.
    Reply
  • WFang
    I'm eagerly anticipating the 600W Passive Seasonic Titanium unit.. I read about it almost a year ago, and still have not seen it tested here ... hope that changes soon.
    Reply
  • LordDrk
    Paid $179 for my EVGA 1000W T2 on ebay =p
    Reply
  • mlga91
    Im not worthy of this one.
    Reply
  • Unolocogringo
    18846027 said:
    There's no need for CF/SLI anymore, the typical PC + RX480/1080 class gpu barely goes above 300w (even less with APU setups or RX460/1050ti). We need way more 400-500w Titanium PSU's.

    We should have 90% efficiency at 50w load with PSU's in that wattage range.

    Just because you do not need one , does not mean others don't.

    I run multiple graphics cards for Folding@Home.The more you can run on each CPU the better. People who run Dual 1080s or dual 39x cards need them to push their 4K monitors.
    So there is a need for them.

    Reply
  • TJ Hooker
    Nintendork said:
    We need way more 400-500w Titanium PSU's.
    We should have 90% efficiency at 50w load with PSU's in that wattage range.
    The thing is, efficiency arguably matters less the lower the power is, because the absolute power being wasted is small. A 500W titanium PSU at max load is only drawing 15W more than a gold rated one. At 50%, 10W. As load drops past 50%, efficiency goes down, but absolute power wasted will still likely go down as well. I don't know, getting a 400W titanium PSU just seems like you're probably paying a lot more money than is necessary for a over engineered PSU which has little to no difference in performance compared to a less efficient, cheaper PSU.
    Reply
  • JV_
    No recommendation award for this one?
    Reply
  • powernod
    Just like Aris stated at his review, i find it amazing how Seasonic managed to generate such a low ripple values without using cable-in capacitors like the rest of the companies do !!
    Reply
  • Aris_Mp
    it has an editor's choice. It will be soon added :)
    Reply