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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nagi603 - Friday, April 7, 2017 - link
Let's hope their eventual redesign won't be as bad as the X-series redesign was. I've had two fail (1 blew on first power-on, the other after half a year) while my original X-400 is still happy as ever after running out of its warranty, regularly driving ~400W of components.Freakie - Saturday, April 8, 2017 - link
In contrast, my 2nd gen X-750 has run like a champ for the last 4 years. My system also doesn't pull more than 450W so I keep the PSU power draw in the sweet spot which is why I got the 750W instead of the 650W.feelingshorter - Saturday, April 8, 2017 - link
I had the X-650, bought when it first came out in 2010 and used it in a computer that i rarely turned off until Jan of 2017 when I sold it. I payed $120 for mine at the time. But the competition is stiff and people are price sensitive, they do not want to hear why they need a PSU that expensive. I can imagine the company had to find ways to reduce costs on the X series, resulting in failures.I believe the PRIME Titanium series offered here represents the best the company can offer and we already know the company can produce a quality product, and quality costs money. The PRIME Titanium, at $160 shipped represents what the X Series was when it first came out.
azazel1024 - Friday, April 7, 2017 - link
They certainly appear to be awesome power supplies. I just wish someone would focus on the low power market for ATX power supplies. I realize as a heavy user, my rigs are rather lightweight, mostly because I have heavy use, but not rigorous gaming. My Desktop running a GTX750 and i5-3570@4GHz sips 122w with an Antec Earthwatts PSU under both gaming and Handbrake loads. I could probably push it up over 140 or 150w with something like furmark, but that doesn't represent a realistic load case. That is with a couple of HDDs, an SSD, 16GB (4x4) GB or DDR3 1866. No, not the most ridiculous system ever, but even if I slapped in something like a 1060 or whatever it is doubtful I'd push the system beyond about 250w.My server is running a Celeron G1610, an SSD and a couple of HDDs with 8GB of DDR3 (2x4GB) and an Intel ET GbE adapter. It sips 19w at idle with the drives spun down, 31w streaming to my AppleTV with the HDDs spun up and about 50w under max CPU load all with a Seasonic SSR-360GP.
Realistically most gamers probably don't even need something with more than about 400w of delivered power and most mainstream users/systems are looking at <200w peak. For some of these lightweight builds it would be really, really nice to see some high efficiency systems in ATX form factors that were targeted more at 100-200w range.
Even my Seasonic SSR-360gp as nice as it is, only manages about 75% efficiency at 19w and its power factor is about .72-.74
mjeffer - Friday, April 7, 2017 - link
While I agree 100%, it would be really nice to see some extremely high quality, lower wattage PSU, from my understanding it's a lot easier for them to hit higher efficiency ratings with higher power PSUs. However, I'd sacrifice the titanium efficiency for a lower power supply with the same top notch components throughout. I'd even pay good money for it. Sadly anything around 400W-500W is generally more focused on price than quality though some of the OEMs like Seasonic do make better ones in that range than you can find in your other brands.Mr Perfect - Saturday, April 8, 2017 - link
Yeah, it's the same thing down in the mITX space. My i7 + 1060 ITX is only pulling ~120ish watts while gaming. Something in the lower wattage range, and preferably in a SFX form factor, would be well suited. Other companies make them, but not in Seasonic's quality range.If I remember correctly, a Seasonic rep used to post comments on reviews of their products here, and he stated that they couldn't source 80+ Gold quality capacitors that would fit in SFX PSUs. I wonder if that's changed in the last few years.
SkipPerk - Wednesday, May 3, 2017 - link
I want to say that Enermax and Seasonic have high-end 400W units that are platinum rated. They are not cheap, but they are really nice. I want to say I saw a review of them compared, but I forgot where. Many of the high-end low power systems are fanless.Chapbass - Friday, April 7, 2017 - link
These units seem really cool, but the thing I really want to see is the 600w fanless unit. Wanted a fanless power supply for a long time.bji - Friday, April 7, 2017 - link
I understand your point of view, as I also appreciate fanless. However, just keep in mind that very few builds are going to stress these power supplies to a point where they'll even turn the fan on. I have a Seasonic 650W from years ago and I am not sure the fan has ever even spun up.JasperJanssen - Saturday, April 8, 2017 - link
Keep in mind the 600W fanless is probably just the 1000W model, minus the fan. Or maybe one of the others, but either way, it'll just literally be one of the other models minus the fan. *Possibly* with larger heatsinks, but I wouldn't count on it.