Cold Test Results

For the testing of PSUs, we are using high precision electronic loads with a maximum power draw of 2700 Watts, a Rigol DS5042M 40 MHz oscilloscope, an Extech 380803 power analyzer, two high precision UNI-T UT-325 digital thermometers, an Extech HD600 SPL meter, a self-designed hotbox and various other bits and parts. For a thorough explanation of our testing methodology and more details on our equipment, please refer to our How We Test PSUs - 2014 Pipeline post.

The Corsair CM450M makes a borderline pass through our efficiency test, just meeting the standards required for 80Plus Gold certification. The energy conversion efficiency reaches 92.1% at 50% load. An average conversion efficiency of 90.2% is achieved within the nominal load range (20% to 100% of the unit's capacity). It seemingly does not perform very well at very low loads, with a conversion efficiency of just 76.1% at 5% load. That however corresponds to an actual load of just 23 Watts and more powerful units would likely fare far worse at so low a load. With a load of 45 Watts, a fairly reasonable figure for the idling state of an average home PC, the conversion efficiency jumps to 83.5%.

As the power output of the CM450M is low and the conversion efficiency is high, it does not have high cooling requirements. Our testing results are not surprising, as the little 450W PSU maintains very low operating temperatures even when heavily loaded. The cooling fan does remain inaudible across most of the load range but it increases its speed at higher loads, reaching audible (but not intrusive) figures. 

The Corsair CS450M PSU Hot Test Results
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  • Black Obsidian - Wednesday, June 10, 2015 - link

    I've used a number of CS450M and CS550M PSUs for budget builds, since they can both regularly be found <$50 (and sometimes <$40, in the case of the reviewed model).

    I've been relying on the Corsair name and warranty as a proxy for actual PSU quality, and I'm quite happy to hear that the quality I'd been assuming actually exists.

    Thanks for prodding manufacturers to provide reasonable-wattage PSUs for review, Fyll!
  • Computer Bottleneck - Wednesday, June 10, 2015 - link

    It actually drops to $26.99 after rebate on a fairly regular basis at Newegg.
  • MapRef41N93W - Thursday, June 11, 2015 - link

    You've been relying on the wrong company then as Corsair are known to release lots of dodgy PSU's in the past. Their "I" series PSUs are hot garbage and usually a complete waste of money compared to the standard series. Their RM series beyond 550 watts suffers from horrible ripple voltage issues. Their CX series (one of the most popular PSU lines due to their extremely cheap price) are not something that should ever be paired with a "high end" setup (like a 4790k/GTX 980) and yet we see this all the time.

    Never trust a single brand of PSUs and always check the OEM of the unit you are buying first. The only real exception to this is Seasonic as they make most of their own PSUs.
  • Zap - Thursday, June 11, 2015 - link

    What is this "horrible ripple" that you speak of? Does it not stay within ATX specifications and manufacturer claims? Or does it just not measure up to "enthusiast" expectations?

    I did a quick search and found "Why you might not want to buy a Corsair RM PSU" on which referenced a TechPowerUp review of the RM1000 as showing the worst performance. The review mentioned a few places where it "failed" such as exceeding ATX specifications for 3.3v ripple at 110% output and OTP triggered at 45°C. Note that both failures exceeds specifications (Corsair rates this PSU to only 40°C).

    The only real fail is in hold-up time, which failed to meet ATX specifications. This would be a good reason to not get this particular PSU, especially if power in your area fluctuates more than normal.

    These PSUs are a far cry from the true "crap" units. Diablotek anyone? Deer? Apevia?
  • Flunk - Thursday, June 11, 2015 - link

    Diablotek units are just as likely to destroy your entire system as work properly so that's not a very good comparison. The previous poster has a point that Corsair's power supplies have a checkered history with certain series (like the CX) being notoriously poor. Maybe this new CS series is them trying to improve their low end offerings, but because Corsair sources power supplies from many, many companies you have to be careful buying from them. Some of their power supplies are great, some are not so great. It's not like Seasonic where they build all their own power supplies.
  • Zap - Friday, June 12, 2015 - link

    My point was that there is a difference between "will destroy your computer" and "horrible ripple but still in spec."
  • PICman - Wednesday, June 10, 2015 - link

    Your reviews are excellent, thanks! For the power efficiency tests, was your mains voltage 220V? Maybe it is listed, but I missed it.
  • Wwhat - Wednesday, June 10, 2015 - link

    There is a link to 'how do we test', on that link page it says:
    "We should note that all testing is being performed with a 230V/50Hz input, delivered by a 3000VA VARIAC for the perfect adjustment of the input voltage. "

    Incidentally 230V is the EU standard.
  • ATC9001 - Wednesday, June 10, 2015 - link

    I understand that high end (i.e. reliable and consistent) equipment for electronics can be expensive, but PLEASE try to convince anandtech to foot the bill so we can get 120V and 230V!

    Great review though, thank you!
  • leexgx - Saturday, June 13, 2015 - link

    230v is optimal for PSUs , where as USA it can be as low as 90V or as high as 120V (why HardOCP tests there PSUs at low voltage as well)

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