Skip to main content

In Win Classic Series C 900W PSU Review

In Win's Classic series consists of only two members featuring 750 W and 900 W capacities. The C900 is our test subject today. Besides a great finish and good looks, it promises reliable and quiet operation, along with high efficiency.

Our Verdict

The C900 has a terrible price per buck ratio, because of its average performance and the enormous price tag. In Win focused more on this unit's cosmetic features instead of providing it with the necessary high performance, which would allow it to survive the competition in the high-end category. Compared to EVGA, Corsair, Seasonic and other similar capacity Platinum and Gold units the C900 doesn't stand a chance with its current price.


  • Full power at 46 °C
  • Ripple suppression
  • Efficient
  • Silent
  • Efficiency under light loads
  • Accurate Power Ok signal
  • Build quality overall
  • Quality caps and cooling fan
  • Low inrush current
  • Fully modular
  • Small dimensions
  • Warranty


  • Price
  • Hold-up time
  • Load regulation
  • Cable configuration
  • No Over Temperature Protection (although it is listed in the unit's specs)
  • Short distance between peripheral connectors

In Win C900 Power Supply Review

In Win has its own PSU production line, which facilitates the manufacturing of special power supplies like the ones in the company's super expensive cases (check out the Signature series). Those massive models look interesting, but you can only get them bundled with In Win enclosures large enough to accommodate them. And given their price tags, it's not easy to obtain review samples.

So, until we can get our hands on a Signature-series PSU, we'll stick with more practical products from In Win like the 900 W Classic-series C900. This model and the C750 debuted recently. We're guessing the company went with the word Classic to describe high quality and a traditional style that never gets old. The flip side is that the C900 has nothing innovative to show; you get familiar honeycomb-style inlet and exhaust grilles. But while the external design might look boring, an aluminum chassis with a hairline brush finish is rarer, so In Win gets some bonus points there. Unfortunately, once you scratch it (not difficult, by the way), the blemish is easy to see.

Without question, the C900 is a premium product. Its $190 price tag reminds you of this. That puts the C900 up against formidable opponents. In order to achieve a decent value score, it needs to perform flawlessly, which won't be easy. In Win might own a PSU production line, but it doesn't have the experience and large engineering teams of OEMs like Delta, Seasonic, and Super Flower. On top of that, limited quantities usually lead to higher prices. That was one reason Enermax had to shutter its own manufacturing lines. 


The C900 boasts 80 PLUS Platinum efficiency and fully modular cables, along with a slow-spinning hypro-bearing fan. We used to complain when we saw fans smaller than 135/140 mm because we knew they'd need to spin fast (and make a lot of noise) to move enough air. In this case, though, In Win used a fan that isn't annoyingly loud, even at full speed.

There is no information available about this PSU's temperature rating. However, that won't stop us from pushing it beyond its limits at >45 °C ambient. Since over-temperature protection is supported, our abuse should be survivable. Finally, the included seven-year warranty is nice and long, though some competitors trump it with 10-year coverage.

Power Specifications

Max. PowerAmps20202525252530.3
Total Max. Power (W)900

There are four +12V rails that, combined, can deliver the unit's full power. The minor rails look weak with their combined 100 W (though no modern system will ever ask for more from those two rails). Lastly, the 5VSB rail has 3 A max current output. We would really love if it was rated at 4 A instead.

Cables And Connectors

Modular Cables
DescriptionCable CountConnector Count (Total)Gauge
ATX connector 20+4 pin (650 mm)1116AWG
4+4 pin EPS12V (660 mm)2218AWG
6+2 pin PCIe (600 mm)4418AWG
SATA (600 mm+100 mm+100 mm)3918AWG
Four-pin Molex (600 mm+100 mm+100 mm) / FDD (+100 mm)26 / 218AWG

Although the C900 is equipped with a couple of EPS connectors and four PCIe ones, not all of them are available at the same time because there are only five eight-pin modular sockets. This simply means you can have either two EPS and three PCIe connectors, or one EPS and four PCIe connectors. For a 900 W unit, a quartet of PCIe connectors is too few, and the issue mentioned above makes matters even worse. Obviously In Win didn't pay enough attention to cable configuration, yielding a major design flaw. That's unfortunate on a $190 PSU.

On the other hand, there are enough SATA and peripheral connectors. We do notice another problem, though: the fixed Berg connector, which won't be utilized by most folks. It should instead be provided through an adapter. Finally, the distance between peripheral connectors is too short at 10 cm. Ideally it would be at least 15 cm.

Power Distribution

The PSU features four +12V rails. But In Win doesn't mention a thing about power distribution and we weren't able to identify the rails. As a result, we can't provide a specifications table this time.

MORE: Best Power Supplies
MORE: Power Supplies 101
MORE: How We Test Power Supplies
MORE: Picking The Right Power Supply: What You Should Know
MORE: All Power Supply Content

Aris Mpitziopoulos
Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.
  • Dark Lord of Tech
    Does the EVGA P2 series have OTP?
  • Aris_Mp
    newer batches have according to my sources. Older ones didn't have.
  • Johan Kryger Haglert
    Terrible bang for the buck you mean.
  • Dark Lord of Tech
    18741010 said:
    newer batches have according to my sources. Older ones didn't have.

    Thank you much appreciated!!!!
  • falchard
    It's not a terrible buy. If you have a beautiful in-Win case, can you really tell yourself the best PSU for the price should be placed in there?