Seasonic G-Series 450W PSU Review

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Pros, Cons And Final Verdict

Without a doubt, Seasonic makes good PSUs. Even its budget lines, where the G series belongs, consist of high-performance units. The G-450 looks like the ideal PSU for small and medium-size systems equipped with a single GPU. It offers good build quality, and it uses Japanese electrolytic capacitors along with quality polymer caps from Enesol. The G-450 also utilizes a double ball-bearing fan that should last for a long time. On top of that, Seasonic backs up the G-450 with a hefty five-year warranty.

However, the G-450 isn't without its faults. The unit has two major drawbacks besides its high price. One is the increased noise output, especially under stressful conditions, because of the fan's high speed and small diameter. The second is lower efficiency, at least compared to the competition's offerings in this category. Seasonic's engineers should make the necessary modifications in this capable platform in order to offer higher efficiency at normal and higher loads, which would also allow for a more relaxed fan profile. 

Lately, the low and mid-capacity PSU categories are seemingly the most popular. This means that the G-450's competition is much higher now than it was about a year ago when this specific model was released with the upgraded platform. Seasonic should take into consideration what users look for in PSUs that belong in this category; other than reliable operation and good overall performance, the company should also pursue quieter operation.

A semi-passive mode isn't required in such low-capacity PSUs, which are usually equipped with fans that can rotate at low speeds. These power supplies don't need high start-up voltages either. On the contrary, a relaxed fan profile and suitable, low-speed fans along with properly-sized heat sinks are essential in creating a PSU that offers quiet operation, even under tough conditions. On top of that, high efficiency is, of course, the number-one priority, since the higher a PSU's efficiency is, the less thermal load its cooling subsystem has to handle. Without a doubt, Seasonic has the necessary know-how to deal with the issues that we found in the G-450.

If you don't mind the increased noise under stress or if you believe that your system's components will cover the PSU's noise under high-load conditions, then the G-450 is definitely a reasonable choice. We should stress, however, that Seasonic asks a lot for this PSU, and for just a bit more money, you can choose from among several top-notch 550W units that offer lower noise output under all conditions.

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Aris Mpitziopoulos is a Contributing Editor for Tom's Hardware, covering Power Supplies.

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Aris Mpitziopoulos
Contributing Editor

Aris Mpitziopoulos is a contributing editor at Tom's Hardware, covering PSUs.

  • InvalidError
    0.4 ohm Rdson is not that bad for primary-side FETs where switching losses tend to be much worse than on-losses.

    Also, FETs with better on-resistance usually have larger gate charge, which means you end up needing more gate drive power to achieve the same switching performance. Saving 3W on full-load on-losses does not sound as good if it costs you 2W in gate drive regardless of load.

    Using FETs with lower on-resistance does not necessarily improve overall efficiency by much.
    Reply
  • TechyInAZ
    Good read. I personally have the 550W version of that PSU and it works very well. Very quiet too, however my entire system doesn't go beyond 350W at max load.

    BTW...The 550W version is usually only $3-$5 more than the 450W. I've never seen the price change either, so it is a bit silly to buy the 450W version if the 550W is always only $5 more.
    Reply
  • Dunlop0078
    I also have the 550watt version, its been going strong for about two years now its very quiet even under load I think I pull about 450watts or so when I have all my overclocks applied. It has been totally stable not a single problem with my PC or the psu since I bought it.

    However I think the price should be lowered a bit for the 550watt version because now it has to compete with the likes of the EVGA 550 G2 which is about the same price but it seems to perform a bit better and comes with a 10 year warranty.
    Reply
  • TechyInAZ
    16760449 said:
    I also have the 550watt version, its been going strong for about two years now its very quiet even under load I think I pull about 450watts or so when I have all my overclocks applied. It has been totally stable not a single problem with my PC or the psu since I bought it.

    However I think the price should be lowered a bit for the 550watt version because now it has to compete with the likes of the EVGA 550 G2 which is about the same price but it seems to perform a bit better and comes with a 10 year warranty.

    10 year warranty!!?? I've been using EVGA graphics cards for years now, I think ill start buying EVGA PSUs now. :D
    Reply
  • Dunlop0078
    16760449 said:
    I also have the 550watt version, its been going strong for about two years now its very quiet even under load I think I pull about 450watts or so when I have all my overclocks applied. It has been totally stable not a single problem with my PC or the psu since I bought it.

    However I think the price should be lowered a bit for the 550watt version because now it has to compete with the likes of the EVGA 550 G2 which is about the same price but it seems to perform a bit better and comes with a 10 year warranty.

    10 year warranty!!?? I've been using EVGA graphics cards for years now, I think ill start buying EVGA PSUs now. :D

    Actually im wrong on that its a 7 year warranty for the 550watt model (still very good in my opinion) the 750watt g2 and above have the 10 year.
    Reply
  • 10tacle
    I know Seasonic is good and an OEM to PSUs for Corsair and whatnot, but I was an unlucky one. My 620W S12II crapped out on an older backup rig after about a year of light use, maybe 250 hours. Unfortunately I voided the 5-year warranty when I had to break the screw seal and open it to get a screw out that accidentally fell in (PC was unplugged when that happened). I figured I'd never need to worry about dealing with a warranty RMA anyway since in nearly 20 years of PC building I've never had one die early on me. WRONG.
    Reply
  • InvalidError
    16760681 said:
    I figured I'd never need to worry about dealing with a warranty RMA anyway since in nearly 20 years of PC building I've never had one die early on me. WRONG.
    Murphy strikes again!
    Reply
  • Blueberries
    This PSU isn't bad but I don't see why anyone would want to pay in the $70's for it when there are gold-- almost platinum rated Leadex PSUs for $80-$90.

    The build quality is what I've come to expect from SeaSonic. Very well built with mostly Nippon Chemi-Con capacitors. Rubycon is also a good brand, and I like to see Infineon MOSFETs in PSUs. This PSU should last forever but isn't very efficient compared to similarly-priced competition.
    Reply
  • turkey3_scratch
    16760497 said:
    16760449 said:
    I also have the 550watt version, its been going strong for about two years now its very quiet even under load I think I pull about 450watts or so when I have all my overclocks applied. It has been totally stable not a single problem with my PC or the psu since I bought it.

    However I think the price should be lowered a bit for the 550watt version because now it has to compete with the likes of the EVGA 550 G2 which is about the same price but it seems to perform a bit better and comes with a 10 year warranty.

    10 year warranty!!?? I've been using EVGA graphics cards for years now, I think ill start buying EVGA PSUs now. :D

    Yeah, aside from the fantastic quality, that was another reason I purchased the G2 over any other PSU.
    Reply
  • tsnor
    "... Seasonic doesn't use a fully modular design in its G series to keep production costs low. Of course, it would be nice if the company changed its strategy and went all-modular on its G-series models since many competing PSUs are, in fact, fully modular...."

    Or maybe they
    (1) know that people will always use the permanent cables that power the MB
    (2) know that two less connectors is a good thing for product reliability
    (3) want to ship a product for people like me that prefer this configuration to a fully modular configuration
    Reply