The Seasonic PRIME Titanium PSU (650W, 750W, 850W) Review: Mythical Performance
by E. Fylladitakis on April 7, 2017 9:00 AM ESTHot Test Results
The electrical performance of the new Seasonic PRIME Titanium units is unbelievable. We are unsure how Seasonic even managed such power quality and performance figures.
| Seasonic SSR-650TD - Main Output | ||||||||
| Load (Watts) | 130.29 W | 325.85 W | 488.11 W | 650.38 W | ||||
| Load (Percent) | 20.04% | 50.13% | 75.09% | 100.06% | ||||
| Amperes | Volts | Amperes | Volts | Amperes | Volts | Amperes | Volts | |
| 3.3 V | 1.78 | 3.34 | 4.45 | 3.34 | 6.67 | 3.33 | 8.89 | 3.33 |
| 5 V | 1.78 | 5.03 | 4.45 | 5.03 | 6.67 | 5.01 | 8.89 | 5.01 |
| 12 V | 9.6 | 12.02 | 24.01 | 12.02 | 36.01 | 12.01 | 48.02 | 12 |
| Line | Regulation (20% to 100% load) |
Voltage Ripple (mV) | |||||
| 20% Load | 50% Load | 75% Load | 100% Load | CL1 12V |
CL2 3.3V + 5V |
||
| 3.3V | 0.2% | 4 | 4 | 6 | 8 | 4 | 6 |
| 5V | 0.25% | 4 | 6 | 6 | 8 | 4 | 6 |
| 12V | 0.15% | 4 | 4 | 6 | 8 | 6 | 6 |
| Seasonic SSR-750TD - Main Output | ||||||||
| Load (Watts) | 150.34 W | 375.71 W | 562.75 W | 750.4 W | ||||
| Load (Percent) | 20.05% | 50.09% | 75.03% | 100.05% | ||||
| Amperes | Volts | Amperes | Volts | Amperes | Volts | Amperes | Volts | |
| 3.3 V | 1.81 | 3.33 | 4.53 | 3.33 | 6.8 | 3.33 | 9.07 | 3.33 |
| 5 V | 1.81 | 5.02 | 4.53 | 5.02 | 6.8 | 5.01 | 9.07 | 5.01 |
| 12 V | 11.25 | 12.02 | 28.11 | 12.02 | 42.17 | 12 | 56.23 | 12 |
| Line | Regulation (20% to 100% load) |
Voltage Ripple (mV) | |||||
| 20% Load | 50% Load | 75% Load | 100% Load | CL1 12V |
CL2 3.3V + 5V |
||
| 3.3V | 0.2% | 4 | 4 | 6 | 8 | 4 | 6 |
| 5V | 0.25% | 4 | 6 | 6 | 10 | 4 | 6 |
| 12V | 0.18% | 4 | 4 | 6 | 8 | 6 | 8 |
| Seasonic SSR-850TD - Main Output | ||||||||
| Load (Watts) | 170.49 W | 426.27 W | 638.38 W | 851.07 W | ||||
| Load (Percent) | 20.06% | 50.15% | 75.1% | 100.13% | ||||
| Amperes | Volts | Amperes | Volts | Amperes | Volts | Amperes | Volts | |
| 3.3 V | 1.84 | 3.34 | 4.6 | 3.34 | 6.91 | 3.33 | 9.21 | 3.33 |
| 5 V | 1.84 | 5.04 | 4.6 | 5.04 | 6.91 | 5.02 | 9.21 | 5.02 |
| 12 V | 12.89 | 12.03 | 32.23 | 12.03 | 48.35 | 12.01 | 64.46 | 12.01 |
| Line | Regulation (20% to 100% load) |
Voltage Ripple (mV) | |||||
| 20% Load | 50% Load | 75% Load | 100% Load | CL1 12V |
CL2 3.3V + 5V |
||
| 3.3V | 0.2% | 4 | 4 | 6 | 8 | 4 | 8 |
| 5V | 0.25% | 4 | 6 | 8 | 10 | 6 | 8 |
| 12V | 0.15% | 4 | 4 | 8 | 10 | 8 | 6 |
We had to check our readings down to the fourth decimal point, as the voltage regulation on the main 12V line is below 0.15%, meaning that a cheap 2-decimal point voltmeter might not even display a difference at all across the entire load range. The 3.3V/5V lines are a little less tightly regulated but still remain amongst the most stable that we have ever seen, with our worst result being 0.24% for the 5V line of the 850W model.
The power quality of all three PRIME Titanium units is insanely good, with our oscilloscope never reading a voltage ripple above 10mV under any operating conditions. We have never seen such effective filtering before on consumer level products.
Despite the exceptional efficiency of the PSUs, the fans are significantly more lively with the units operating into our hotbox, as the thermal control circuit is trying to maintain low internal operating temperatures. The PRIME Titanium units all begin with noise figures when lightly loaded but their fans will keep increasing their speed alongside with the load, reaching clearly audible figures with loads above 300 Watts and even becoming noisy with >46 dB(A) figures when they units are very heavily loaded. The maximum temperature that our instruments recorded was just below 80 °C, which is very low for an 850W PSU operating at maximum capacity, meaning that Seasonic could trade some of the thermal performance for better acoustics. These units do come with a 12-year warranty though, so the designer could perhaps not afford >90°C figures appearing into any of these units.
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TEAMSWITCHER - Saturday, April 8, 2017 - link
This site isn't nearly as useful as it once was....Ian Cutress - Monday, April 10, 2017 - link
Care to elaborate?crashtech - Saturday, April 8, 2017 - link
All these need is a Hobbs meter, they sound like a rock you can build many a system upon.Stele - Sunday, April 9, 2017 - link
Well-written review as usual, offering a good balance between technical detail and readability. I have however noticed that you use the term "primary conversion bridge" in your PSU reviews. I believe you're referring to the component which converts AC to DC; if so, it's properly called a "bridge converter". That aside, do keep up the good work!surt - Sunday, April 9, 2017 - link
In what country? Around here primary conversion bridge is definitely the correct term.Stele - Monday, April 10, 2017 - link
Actually in many if not most English-speaking countries. Countries aside - it's also used by the semiconductor industry, including manufacturers themselves. For just a few examples:-http://www.infineon.com/cms/en/product/transistor-...
http://my.element14.com/bridge-rectifier-diodes?se...
https://www.digikey.com/products/en/discrete-semic...
http://www.mouser.com/Semiconductors/Discrete-Semi...
http://www.vishay.com/diodes/rectifiers/bridge/
https://www.fairchildsemi.com/products/discretes/d...
And in standard electronic texts - try Cedra & Smith, Microelectronic Circuits (any edition).
I was an electrical engineer :)
Stele - Monday, April 10, 2017 - link
I hasten to add my original post was itself erroneous - I meant to say "bridge rectifier" not "bridge converter". Not enough coffee!mobutu - Sunday, April 9, 2017 - link
The only thing I'm interested in from this series is the minimum wattage option, the 600W fanless.And also hope that seasonic will offer lower wattage also in this product line. (like 300-500W range)
I'll never use more than one GPU so have no use for PSUs more than 500-600W, even overclocked.
Hxx - Monday, April 10, 2017 - link
for the price they should have included paracord cablesLaststop311 - Monday, April 10, 2017 - link
I have the 750 watt version and it's a work of art. Either than fan has never spun up or i cant hear it. Even with a 5.0ghz overclock 7700k cooled with a nh d15s and thermal grizzly liquid metal with the ultra low speed adapters for the fans. Inside a fractal define r5 with 2x 140mm venturi HF intake fans and 1x 140mm fractal exhaust that comes with it. controlled with asus fanxpert. System is dead quiet and powers everythng like a boss. paired with an rx 480 overclocked to the max since i have a free sync monitor. im happy with 144hz 1920x1080 gaming on a curved 27" acer predator. Thank you seasonic for making the best PSU ever made.