Seasonic Prime 850 W Titanium PSU Review

Seasonic made an impressive entry in the 80 PLUS Titanium category with its Prime series. This line's current flagship, offering 850W capacity, is being reviewed today. Besides high efficiency, it sports quiet operation and top performance.

We already reviewed the Seasonic Prime 650, which impressed us enough to roll out a rare Editor's Choice award. Today we're testing the top member of Seasonic's Titanium Prime family, offering up to 850W of maximum capacity and similar specs as the last model we evaluated. Without a doubt, this company rocked the boat with its high-end Prime series, based on a new platform.

The Prime 850 W Titanium, or SSR-850TD, features compact dimensions and fully modular cabling. In addition to high efficiency and exemplary performance, the PSU also promises quiet operation. There are two fan modes, normal and hybrid, which can be selected through a push-button located on the front panel. As a result of its Titanium-class efficiency, the SSR-850TD doesn't dissipate much waste heat, so there's no reason for an aggressive fan profile or high rotational speed. On top of that, Seasonic finally got over its obsession with 120mm fans and equipped the Prime family with a larger cooler. It is nice to see Seasonic focusing more on quieting down its products; previously, the Snow Silent units were the only ones able to match Super Flower's high-efficiency offerings.

As an aside, we are anticipating the release of new Prime models soon, since this line will consist of more affordable Gold- and Platinum-rated units as well. In addition, we will likely see the Prime platform branded by other companies partnering with Seasonic.

Specifications

Titanium-class efficiency, a single +12V rail, modular cabling, and a 50°C maximum output rating are all highlights of this design. In addition, the SSR-850TD is covered by a full suite of protection features that includes over-temperature protection.

The cooling fan uses a Fluid Dynamic Bearing, which offers a 70,000-hour lifetime at 40°C. In comparison, high-quality double ball-bearing fans are rated for 50,000 hours and sleeve-bearing ones go up to 30,000 hours. There are some FDB fans with much higher ratings, but their manufacturers don't specify a maximum temperature. Seasonic, on the other hand, is crystal clear on the matter. We appreciate when a manufacturer doesn't hide such important details.

Finally, Seasonic guarantees its workmanship for 10 years. The company is clearly gunning for Corsair and EVGA with its extra-long warranty.

Power Specifications

Rail3.3V5V12V5VSB-12V
Max. PowerAmps20207030.3
Watts100840153.6
Total Max. Power (W)850

The single +12V rail can deliver up to 70A of current, which should be plenty for a high-end gaming system with a couple of flagship graphics cards. On the other hand, the minor rails are limited to 100W combined, though that's still enough for any modern PC. The 5VSB rail is stronger than usual with 15W maximum power output.

Cables And Connectors

Modular Cables
DescriptionCable CountConnector Count (Total)Gauge
ATX connector 20+4 pin (610mm)1118AWG
4+4 pin EPS12V (650mm)2218AWG
6+2 pin PCIe (675mm+75mm)3618AWG
SATA (450mm+120mm+120mm+120mm)2818AWG
SATA (350mm+120mm)1218AWG
Four-pin Molex (450mm+120mm+120mm)1318AWG
Four-pin Molex (350mm+120mm)1218AWG
FDD Adapter (+100mm)1122AWG

The provided cables are quite long, so you probably won't have problems with full-tower cases. However, we'd like to see more distance between the SATA and peripheral connectors (at least 15cm). We do appreciate the fact that Seasonic provides a set of short SATA and four-pin Molex cables for use in smaller enclosures. And we also like the FDD adapter, since fixed Berg connectors aren't often used these days and they only serve to make cable management harder. Lastly, the number of provided connectors is ample for this unit's capacity; Seasonic gives us access to six PCIe connectors and a couple of EPS ones at the same time.

Power Distribution

Since this PSU features a single +12V rail, we do not have anything to say about its power distribution.

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  • trampus123
    I want one
  • 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.
  • 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.
  • LordDrk
    Paid $179 for my EVGA 1000W T2 on ebay =p
  • mlga91
    Im not worthy of this one.
  • Unolocogringo
    Anonymous 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.
  • 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.
  • JV_
    No recommendation award for this one?
  • 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 !!
  • Aris_Mp
    it has an editor's choice. It will be soon added :)
  • bit_user
    Anonymous said:
    The thing is, efficiency arguably matters less the lower the power is, because the absolute power being wasted is small.
    I have a 130 W CPU and a 275 W graphics card that spend most of their time idling. I need a pretty big PSU for when they're being stressed, but I want efficiency for the 99% of the time my system spends at 10-20% load.
  • TJ Hooker
    @bit_user I understand where you're coming from, but like I said, even though wasted power as a percentage may be relatively high at low loads, in absolute terms it's quite low. Like 10W from my previous example. That's going to have virtually zero effect on your power bill, and negligible effect on PSU operation. If you're the kind of person who values efficient operation on principle, I get that, I just don't think it's really justified from a practical perspective.
  • bit_user
    Anonymous said:
    @bit_user I understand where you're coming from, but like I said, even though wasted power as a percentage may be relatively high at low loads, in absolute terms it's quite low. Like 10W from my previous example.
    Yes, 10W seems like a reasonable ballpark. My power costs me about $0.50 / kWh. If I leave that PC on 24/7, that's almost $4/month. And let's not forget that this is plugged into my UPS, which has its own inefficiencies. And, in the summer, I have to pay again, in order to remove the waste heat from that room via A/C or fans. But I don't pay for heat (it's included in my rent), so it doesn't help during the winter.

    My PC probably idles somewhere in the neighborhood of 85 W, while its current PSU is 860 W (yeah, a little bit overkill). So, about 10%. But 80 Plus only specifies efficiency for 10% load for the Titanium level, so it could be worse than 80% efficiency @ 10% load.

    Now, it so happens that PSU is a Seasonic Platinum model, and I'm definitely not replacing it just for the added efficiency of Titanium. However, if I were buying a new PSU, I'd tend to go for titanium unless doing so involved a tradeoff vs. performance or a significant price difference.

    TBH, I don't leave that PC on 24/7, but it does sometimes stay on (and not sleeping) for days at a time.
  • TJ Hooker
    Anonymous said:
    Anonymous said:
    @bit_user I understand where you're coming from, but like I said, even though wasted power as a percentage may be relatively high at low loads, in absolute terms it's quite low. Like 10W from my previous example.
    Yes, 10W seems like a reasonable ballpark. My power costs me about $0.50 / kWh. If I leave that PC on 24/7, that's almost $4/month. And let's not forget that this is plugged into my UPS, which has its own inefficiencies. And, in the summer, I have to pay again, in order to remove the waste heat from that room via A/C or fans. But I don't pay for heat (it's included in my rent), so it doesn't help during the winter.

    I don't know what average electricity rates are around the world, but considering it's only $0.05-0.08/kWh where I live, it seems like $0.50/kWh is towards the higher end. So with those rates and leaving your PC on 24/7, that's close to a worst case scenario, and it would still likely take months to recoup the extra cost of a titanium PSU. And of course a PC can always be turned off/asleep when not in use, which would significantly lengthen the amount of time necessary to recoup your money.

    Don't know what kind of efficiency your UPS has, but unless it's heinously inefficient it should't be more than a few watts of loss on a 10W load. Cost of removing 10W via A/C should be trivial. There are numerous devices within a home using orders of magnitude more power. Even a human's basal metabolic rate is far higher than that, so just having someone just sitting in the same room is enough to make a 10W load relatively insignificant.

    You're right though, in the case of this Seasonic, you're not just paying for increased efficiency, you're also paying for a top notch platform. But I'm not arguing against this Seasonic. I'm arguing against the importance of ultra-efficient low wattage PSUs in general, especially because efficiency and overall PSU quality aren't necessarily linked.
  • bit_user
    Anonymous said:
    I don't know what average electricity rates are around the world, but considering it's only $0.05-0.08/kWh where I live, it seems like $0.50/kWh is towards the higher end.
    My bad. It's closer to $0.20.
  • bissag
    Can the high Inrush current cause damage to components?