# Seasonic PRIME Series 750 W



## crmaris (Nov 7, 2016)

We evaluate Seasonic's Prime 750 unit, which boasts amazing performance, including 80 PLUS Titanium efficiency, a set of interesting features, and a unique look. Seasonic has an impressive Titanium entry on their hands that will make other OEMs feel uncomfortable because it raises the performance bar incredibly high.

*Show full review*


----------



## dj-electric (Nov 7, 2016)

Many people have already crowned the PRIME series as the best power supplies in PC history.
Its really not hard to see why.


----------



## Grings (Nov 7, 2016)

I really wish i had got the 850w version now, but was messing about with r9 390's in crossfire so got an evga 1000w

This current card (1070) would probably be fine sli'd to another on the 650w prime


----------



## Nuckles56 (Nov 7, 2016)

Damn, I want one, even though I have no need for anywhere near 750W of power as it is so quiet and performs incredibly well. Too bad they are priced near $300 where I live


----------



## Devils41 (Nov 7, 2016)

Great review I just picked this power supply up for $109 on sale from Newegg a month ago. I replaced a 850W thermaltake smart m 80+ bronze, Im happy I made the switch for the 10 year warranty alone.


----------



## arnold_al_qadr (Nov 8, 2016)

large inrush current, about 57 ampere, so this psu will definitely trip a 6 ampere 220 volts circuit breaker?


----------



## crmaris (Nov 8, 2016)

the inrush current is applied for a very short period and the circuit breakers usually have a short delay before they react, so it might not trip it. However 6A are very low.


----------



## arnold_al_qadr (Nov 8, 2016)

in indonesia is still common for small family have 1300va electricity for their household, the place that i rent right now have 900va electricity.


----------



## Assimilator (Nov 8, 2016)

While it's great to see the Prime series performing so well, I'm still waiting for Seasonic to release the Focus series. Given that PCs are becoming more and more efficient, I feel like there is a massive untapped market for lower-wattage higher-efficiency units, and Focus should hopefully fill that gap. I reckon a 450W Focus Platinum would run my current setup just fine.


----------



## sith'ari (Nov 8, 2016)

As i was reading the review, i was becoming more and more certain that we will see a huge score for the SS Prime750!! So when i saw the *9,8* i wasn't surprised in the least  
Great unit indeed, as well as a great review as always!!

P.S. I have one question for Aris though: Do we have any explanation about the deviation we witnessed at 12V crossload tests between the Prime750 and the Prime650 at your review at Tom's? (the 750 here is 2%, while the 650 unit was hitting 3%)


----------



## Joss (Nov 8, 2016)

> Take a closer look at the table above and you will notice that the cooling fan actually slows down at 70% and 80%, the unit's max-rated capacity, which also quietens down the fan. This happens because the fan doesn't increase its speed linearly as it should when its input voltage increases from 2.4 V to a little over 3 V; it drops in speed instead. _*We don't know the reason behind this strange design choice*_. There's probably a trick to allow for the fan's low start-up voltage since 2.4 V is quite low for a 135mm fan, and it somehow leads to the fan's strange speed curve with low voltage input.


Are we sure it's by design, couldn't it be an issue?


----------



## jabbadap (Nov 8, 2016)

Joss said:


> Are we sure it's by design, couldn't it be an issue?



Probably not, most likely it's just changing the fan controlling hysteresis to coolingmode. Seasonic have their hybrid fan control curvatures at 25°C ambient. This test is done on 40-46°C ambient, which might or might not explain the anomaly. But curvature is still quite the same, there's fanless mode, hysteresis mode and finally cooling mode.


Spoiler: S3FC


----------



## bug (Nov 8, 2016)

For my past 2-3 PSUs I wanted to get a passive cooled unit. I don't SLI/Crossfire, so I don't need much power. Whether the passive units were not being imported at the time or simply out of stock, I always ended up with active cooling. The 600W of these looks sweet, but I'm not exchanging my perfectly good Seasonic PSU


----------



## R-T-B (Nov 8, 2016)

I just bought a EVGA based on a Superflower Titanium design out of impatience not but a few months ago...  damn.


----------



## buzzi (Nov 8, 2016)

Thank you for review!

@Assimilator what about Platinum 400 (fanless)?


----------



## nem.. (Nov 9, 2016)

Fantastic work of Seasonic, i cant wait for the XFX line based on Seasonic prime 

http://orionpsudb.com/news/xfx-will...gold-line-as-the-xfx-xti-xts2-and-xtr2-series


----------



## crmaris (Nov 9, 2016)

sith'ari said:


> P.S. I have one question for Aris though: Do we have any explanation about the deviation we witnessed at 12V crossload tests between the Prime750 and the Prime650 at your review at Tom's? (the 750 here is 2%, while the 650 unit was hitting 3%)



This is the deviation with the nominal voltage (12V) as point zero and not the voltage of this rail with 20-40W load.


----------



## R-T-B (Nov 9, 2016)

Bah.  I caved and bought one of these units.  Watch for a super cheap EVGA T2 850W Titanium coming on sale soon from a frog near you!


----------



## Assimilator (Nov 10, 2016)

buzzi said:


> Thank you for review!
> 
> @Assimilator what about Platinum 400 (fanless)?



Not available in my country. :/ (Neither is the Prime series, but I'm hoping that will change.) Also I have an aversion to putting a completely fanless PSU in my main machine - dunno why but knowing the fan is there if necessary is comforting.


----------



## jabbadap (Nov 10, 2016)

Assimilator said:


> Not available in my country. :/ (Neither is the Prime series, but I'm hoping that will change.) Also I have an aversion to putting a completely fanless PSU in my main machine - dunno why but knowing the fan is there if necessary is comforting.



XFX XTS maybe(made by seasonic)?


----------



## buzzi (Nov 13, 2016)

Assimilator said:


> dunno why but knowing the fan is there if necessary is comforting



same for me.


----------



## nem.. (Dec 2, 2016)

crmaris said:


> This is the deviation with the nominal voltage (12V) as point zero and not the voltage of this rail with 20-40W load.



then the 650w unit is not an FLOP as say HardOCP because this situation ?  its was confused for me see that conclusion in hardocp but as i understan was just about 650 unit


----------



## RejZoR (Dec 3, 2016)

Very clean layout I must say. I just (still) don't like the cheap looking fans they use, despite the fact it's FDB fan. By looking at it I'm getting the impression it's a cheap sleeve bearing fan... I mean, has anyone seen the fans inside BeQuiet's Dark Power Pro PSU's? I'm pointing it out coz I have it and because none of other PSU's impressed me as much as this one when it comes to fan selection. FDB fan with specially carved blades for minimum noise. It's so quiet regardless of load it's ridiculous.


----------

