Seasonic s12g 650w review: Seasonic S12G 650W Power Supply Review

Seasonic S12G 650W — Best Compatible Seasonic S12G 650W PSU


Seasonic S12G 650W

The Seasonic S12G 650W has a maximum capacity of 650 Watts.

It has an 80 Plus rating of Gold and its dimensions (LxWxH) are 140cm x 150cm x 86cm.

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Seasonic S12G 650W

Seasonic S12G 650W compatibility review

The Seasonic S12G 650W power supply has a maximum wattage output of 650W. This is a decent capacity, and should be fine at handling the majority of mid-performance PC builds, but you could find yourself in trouble if you do not make certain of its capability to power any proposed build. Remember that a higher PSU capacity does not necessarily equate to a higher wattage output and a more expensive electricity bill. In fact, you may find that a higher capacity PSU will function more efficiently than a lower capacity PSU because it is dealing with a lower percentage of its maximum load — that is, it is not being stressed to the same extent.

The Seasonic S12G 650W has an 80 Plus rating of Gold. This means the PSU operates at average efficiency levels of at least 87%, 90%, and 87% for loads of 100%, 50%, and 20% respectively. Gold is the second-best 80 Plus certificate available, and as such the Seasonic S12G 650W is extremely efficient and comes highly recommended.

The dimensions of the Seasonic S12G 650W (LxWxH) are 140cm x 150cm x 86cm. Make sure to compare these measurements against the case you desire if planning on using it in a build.

The Seasonic S12G 650W is not modular, meaning that cables are built into the PSU itself and cannot be taken out and connected back in as necessary. This can result in difficult cable management and consequently a messy build and poor airflow.

The Seasonic S12G 650W is not designed for low volumes, meaning that its constant drone while your PC is on could potentially be noticeable and irritating, though this may only be a problem for those that require silent environments.

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Seasonic S12G 450 W — 80PLUS Gold Power Supply Roundup — Tom’s Hardware

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Seasonic S12G 450 W

In past round-ups, Seasonic fared well with its X family of power supplies. They’re notably fully modular and equipped with dynamic fan control. Additionally, the company is known for its fantastic build and component quality.

But for this story, Seasonic sent us the 450 W version of its S12G. For a price right around $75, you get a compact, 80 PLUS Gold-certified PSU with completely fixed cabling. That makes the S12G the only power supply in our round-up without cable management. In return, a combination of sleeved, round cables and flat cables turn out to be the long side, giving you plenty of room for routing. Moreover, you get two auxiliary PCIe connectors and eight for SATA-based drives.

Surprisingly, Seasonic’s build quality doesn’t quite match up to the competition. Similarities we do find are a single +12 V rail rated for up to 37 A and five-year warranty coverage.

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AC Input 100-240 V, 50-60 Hz
DC Output +3. 3 V + 5 V +12 V (#1) +12 V (#2) +12 V (#3) +12 V (#4) -12 V +5 Vsb
20 A 20 A 37 A n/a n/a n/a 0.3 A 2.5 A
Individual Output 32 A 3.6 W 12.5 W
Rail Utilization Sys Sys CPU & VGA
Combined Output 100 W 444 W
Total Continuous Output 450 W
Peak Output n/a

Seasonic’s X line is typically a top contender in our performance measurements. The less-expensive S12G still has something to prove, though. It does master our efficiency testing, according to the 80 PLUS specification, and even has a bit of room to spare.

At very low loads, the S12G’s efficiency is about the same as Corsair’s RM450. At 25 W, it tails Cooler Master’s V450S by about 10 percent. But in standby, without any load, Seasonic has the only PSU able to compete with the RM450 by demonstrating .05 W of consumption.

For those of you keeping score at home, that means this PSU hasn’t exhibited any real weaknesses yet. The ripple and noise measurements continue along the same lines. There’s barely any ripple, and the curve is pretty smooth.

Thanks to its hybrid cooling solution, Corsair’s RM450 just can’t be beaten when it comes to acoustics. Seasonic often triumphs in this metric. However, the company chooses not to use the dynamic cooling we’ve come to appreciate from its X family. That doesn’t mean the S12G is loud. Quite the opposite. It’s fan is on the quiet side, registering between 30.9 and 31.3 dB(A).

A Look at the PCB

There’s no cable management, no hybrid fan control, and Seasonic sneaks in with the lowest price in today’s story. Did the company have to cut some corners when it was picking components and putting the S12G together? Nope. We find a DC-to-DC converter topology with LLC, as well as a very good input filter including two X and six Y capacitors, three choke coils, and a MOV.

Hitachi supplies the primary capacitor. On the secondary side, there are a number of capacitors from the South Korean manufacturer Enesol, as well as a few by Chemi-Con and Rubycon. All in all, the parts are higher-quality than what we found from the other power supplies in our round-up. And then there’s the immaculate soldering work.

The bottom line is that Seasonic does everything right for a PSU in this price category for both component selection and build quality.

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