Seasonic G-Series 450W PSU Review

Seasonic's G series consists of reliable, high-performance PSUs. Today, we're reviewing the G-450 with 450W capacity, which features a semi-modular cabling design.

Seasonic is a well-known company in the PSU market; in addition to retail sales, its platforms are also used by many other companies, including Antec, Corsair, EVGA and Fractal Design. One of Seasonic's budget Gold-rated lines is the G series, which consists of five products with capacities ranging from 360 to 750W. Today we're looking at the G-450, which, as its model number implies, offers up to 450W of capacity.

All G-series power supplies use a semi-modular cabling design, have compact dimensions and are cooled by a 120mm fan. In addition, they are backed by a five-year warranty, which is rather long for the standards of this category. Seasonic claims that the performance of its G-series PSUs is top-notch, and we believe the company since we've tested a number of models in this line, including units based on the same platform. The results were very good in all cases.

The G-450 is a high-quality low-capacity PSU able to cover not only entry-level systems but also mid-range ones with respectable GPUs (thanks to its two auxiliary PCIe connectors). Power supplies like this are popular with enthusiasts who know they don't need massive output, only to use a fraction of it. Typically, lower-wattage PSUs achieve significantly higher efficiency at light loads compared with more powerful PSUs, so if your system's energy needs are low, then you should avoid buying a high-capacity supply. Otherwise, you'll pay more for the unit itself and incur increased operational costs compared to a less-powerful model offering the same efficiency characteristics. On the other hand, if you plan to add a second graphics card, you'll need a power supply with at least four PCIe connectors and 500W+ capacity. The G-450 would fall short in that case.

Specifications

Besides 80 PLUS Gold efficiency, the G-450 is also Haswell-ready and can deliver its full power continuously at up to 50 degrees Celsius (122 degrees Fahrenheit) ambient temperature. This is a clear indication that it is based on a solid platform with good components that are able to withstand tough conditions. The PSU offers all necessary protections, including OCP (over-current protection), even though it sports a single +12V rail. We typically don't see OCP in PSUs with one +12V rail; Seasonic most likely added this protection because of the unit's low capacity.

Cooling is handled by a 120mm double ball-bearing ADDA fan. It's a good-quality cooler that should work flawlessly for many years. And even though the price is on the high side, we believe the build quality of this product justifies it.

Power Specifications

Rail3.3V5V12V5VSB-12V
Max. PowerAmps20203730.3
Watts10044412.53.6
Total Max. Power (W)450

The single +12V rail can deliver the PSU's full power alone; it has enough amperage to feed a high-end GPU. The minor rails are strong for a modern system that is covered by a 450W power supply, and the 5VSB rail has the typical capacity for a contemporary PSU.

Cables & Connectors

Modular Cables
DescriptionCable CountConnector Count (Total)
ATX connector 20+4 pin (550mm)11
4+4 pin EPS12V (570mm)11
Native Cables
6+2 pin PCIe (610mm)22
SATA (400mm+115mm+115mm+115mm)14
SATA (300mm+115mm)12
Four-pin Molex (400mm+120mm+120mm)13
Four-pin Molex (300mm+120mm)12
FDD Adapter (+110mm)11

This unit has the typical cable/connector configuration for a respectable low- to mid-capacity PSU. Seasonic equips it with a single EPS connector and a pair of PCIe connectors, through which the G-450 can easily deliver its full power. In addition, six SATA and five four-pin peripheral Molex connectors are more than enough for this category.

Overall, cable length is adequate with one exception: the EPS cable, which in our opinion should be at least 60 centimeters in length. All connectors use 18-gauge wires, which are recommended by the ATX spec.

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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18 comments
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  • 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.
  • 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.
  • 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.
  • TechyInAZ
    1580297 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
  • Dunlop0078
    Quote:
    1580297 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.
  • 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.
  • InvalidError
    202972 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!
  • 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.
  • turkey3_scratch
    1695593 said:
    1580297 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.
  • 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
  • InvalidError
    200136 said:
    (3) want to ship a product for people like me that prefer this configuration to a fully modular configuration

    On a normal day, I would agree that modular cables are way overrated. Even if I had a modular PSU, I would probably end up putting all the cables in the case anyway just to make sure I won't lose any.

    On the other hand, my PSU's fan started rattling intermittently a few weeks ago. If I had a modular PSU, I could get the PSU out, lube/swap the fan and put the PSU back in in something like 15 minutes. With hard-wired cables though, it will probably take me more than an hour to remove all the wiring tucked away behind the motherboard tray and put it back, so I decided to forgo the repair until it sounds more urgent.
  • Blueberries
    125865 said:
    200136 said:
    (3) want to ship a product for people like me that prefer this configuration to a fully modular configuration
    On a normal day, I would agree that modular cables are way overrated. Even if I had a modular PSU, I would probably end up putting all the cables in the case anyway just to make sure I won't lose any. On the other hand, my PSU's fan started rattling intermittently a few weeks ago. If I had a modular PSU, I could get the PSU out, lube/swap the fan and put the PSU back in in something like 15 minutes. With hard-wired cables though, it will probably take me more than an hour to remove all the wiring tucked away behind the motherboard tray and put it back, so I decided to forgo the repair until it sounds more urgent.


    This is an excellent point, actually. I prefer the look of soldered cables, especially when there's no leftovers or semi-modular adaptability, but having a modular PSU is just too nice. I think you hit the nail on the head here.
  • RedJaron
    200136 said:
    "... 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

    Yeah, I prefer semi-modular PSUs too. The 24-pin mboard and 4+4-pin CPU cables are always used. A single fixed PCIe 6+2 cable generally isn't amiss either, depending on wattage capacity ( on 450W and up ). Fixed SATA/peripheral power cables are iffy since it's hard to generalize how long you need those cables or whether you need two, four, or more connectors on the cable.
  • Brian_R170
    Quote:
    On the other hand, my PSU's fan started rattling intermittently a few weeks ago. If I had a modular PSU, I could get the PSU out, lube/swap the fan and put the PSU back in in


    Don't forget just pulling your PSU regularly to do a thorough compressed-air dusting. A fully modular PSU definitely makes that easier. I still prefer a semi-modular PSU, though, just for the reduction in connections. I just make sure not to overly wire-manage the non-modular cables.
  • InvalidError
    1696401 said:
    Don't forget just pulling your PSU regularly to do a thorough compressed-air dusting.

    Dust inside my cases is rarely a problem since I have air filters. 99% of the dust does not make it to the fans.

    I had already gone through the trouble of removing that PSU from my case due to "Anti-Surge" shutdowns a year ago to see if it may have been caused by caps failing. After not finding anything visually wrong in the PSU, not even any dust worth mentioning, I noticed while putting the PSU back in that the case's PSU filter was completely clogged. No more anti-surge issues since and my room temperature hit 40C a few times during summer.

    Dedicated PSU intakes sound nice in theory. In practice, I do not like the idea of my PSU randomly acting up due to a clogged filter I cannot see.
  • TechyInAZ
    125865 said:
    1696401 said:
    Don't forget just pulling your PSU regularly to do a thorough compressed-air dusting.
    Dust inside my cases is rarely a problem since I have air filters. 99% of the dust does not make it to the fans. I had already gone through the trouble of removing that PSU from my case due to "Anti-Surge" shutdowns a year ago to see if it may have been caused by caps failing. After not finding anything visually wrong in the PSU, not even any dust worth mentioning, I noticed while putting the PSU back in that the case's PSU filter was completely clogged. No more anti-surge issues since and my room temperature hit 40C a few times during summer. Dedicated PSU intakes sound nice in theory. In practice, I do not like the idea of my PSU randomly acting up due to a clogged filter I cannot see.


    You never knew the dust filter was there?
  • InvalidError
    1695593 said:
    You never knew the dust filter was there?

    I knew it was there but it is a PITA to install/remove and I was not expecting it to clog up that quickly and thoroughly.

    To make sure this won't happen again, I removed a chunk of the gasket between the case/intake and PSU.
  • 10tacle
    On my backup rig that has a downward-intake for the PSU from the bottom, I solved my PSU bottom dust filter (which was black) problem by removing the case PSU filter screen and cutting up a 24"x24" HVAC filter screen (which is white and easy to tell when needing changing) into 6"x6" pieces and taping one to the bottom on the outside. It takes all of about 90 seconds to do and who cares what it looks like since nobody sees the bottom of my case. This only works though with the case slightly elevated off the surface to allow clearance for the ~1/2" height of the filter.