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Corsair TX550M Power Supply Review

The TX550M is another good PSU by Corsair.

Corsair TX550M
(Image: © Tom's Hardware)

To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units. 

Primary Rails And 5VSB Load Regulation

The following charts show the main rails' voltage values recorded between a range of 40W up to the PSU's maximum specified load, along with the deviation (in percent). Tight regulation is an important consideration every time we review a power supply because it facilitates constant voltage levels despite varying loads. Tight load regulation also, among other factors, improves the system’s stability, especially under overclocked conditions and, at the same time, it applies less stress to the DC-DC converters that many system components utilize.

Load regulation is tight on all rails! The fixed cables play role in this. 

Hold-Up Time

Put simply; hold-up time is the amount of time that the system can continue to run without shutting down or rebooting during a power interruption.

The hold-up time is close to 21ms, and the power ok signal is accurate and over 16ms, so everything is fine here. 

Inrush Current

Inrush current, or switch-on surge, refers to the maximum, instantaneous input current drawn by an electrical device when it is first turned on. A large enough inrush current can cause circuit breakers and fuses to trip. It can also damage switches, relays, and bridge rectifiers. As a result, the lower the inrush current of a PSU right as it is turned on, the better.

The inrush current is low with 115V, but higher than expected with 230V. 

Leakage Current

In layman's terms, leakage current is the unwanted transfer of energy from one circuit to another. In power supplies, it is the current flowing from the primary side to the ground or the chassis, which in the majority of cases is connected to the ground. For measuring leakage current, we use a GW Instek GPT-9904 electrical safety tester instrument.

The leakage current test is conducted at 110% of the DUT's rated voltage input (so for a 230-240V device, we should conduct the test with 253-264V input). The maximum acceptable limit of a leakage current is 3.5 mA and it is defined by the IEC-60950-1 regulation, ensuring that the current is low and will not harm any person coming in contact with the power supply's chassis.

Corsair TX550M

(Image credit: Tom's Hardware)

Leakage current is low. 

10-110% Load Tests

These tests reveal the PSU's load regulation and efficiency levels under high ambient temperatures. They also show how the fan speed profile behaves under increased operating temperatures.

Test12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan Speed (RPM)PSU Noise (dB[A])Temps (In/Out)PF/AC Volts
10%2.783A2.008A2.008A0.992A54.99181.733%86421.440.01°C0.933
11.997V4.979V3.287V5.038V67.28145.39°C115.15V
20%6.589A3.013A3.013A1.192A109.91987.913%86821.640.64°C0.968
11.992V4.978V3.286V5.032V125.03246.36°C115.15V
30%10.749A3.517A3.516A1.392A164.90790.159%86721.541.09°C0.976
11.988V4.977V3.285V5.027V182.90747.38°C115.14V
40%14.939A4.02A4.02A1.593A219.9890.829%87021.641.93°C0.983
11.967V4.976V3.283V5.022V242.19148.48°C115.14V
50%18.766A5.027A5.028A1.794A274.96690.815%93324.042.23°C0.987
11.961V4.974V3.282V5.017V302.77749.44°C115.14V
60%22.594A6.034A6.036A1.995A329.95290.54%96325.242.84°C0.989
11.956V4.973V3.28V5.011V364.42850.67°C115.14V
70%26.435A7.041A7.046A2.196A384.91590.169%97425.743.01°C0.991
11.947V4.971V3.278V5.006V426.88451.38°C115.15V
80%30.261A8.002A8.053A2.298A439.10589.48%116931.243.81°C0.992
11.945V4.97V3.277V5.001V490.73152.71°C115.14V
90%34.495A8.552A8.545A2.401A494.34488.833%126632.944.35°C0.993
11.940V4.969V3.276V4.996V556.4953.85°C115.13V
100%38.526A9.058A9.067A3.005A549.55187.99%140236.245.93°C0.993
11.937V4.967V3.274V4.99V624.56356.24°C115.12V
110%42.431A10.067A10.172A3.008A604.57187.065%151537.846.82°C0.993
11.932V4.966V3.273V4.985V694.39257.69°C115.12V
CL10.115A14.508A14.537A0A121.27183.257%111529.642.37°C0.971
11.991V4.977V3.281V5.021V145.65949.27°C115.14V
CL20.114A20.074A0A0A101.37782.481%100727.043.17°C0.967
11.996V4.982V3.282V5.03V122.9150.73°C115.14V
CL30.114A0A25.103A0A83.86776.627%98726.344.77°C0.964
11.991V4.975V3.286V5.024V109.4553.57°C115.14V
CL445.993A0A0A0A549.38689.347%135235.045.78°C0.993
11.945V4.972V3.281V5.007V614.89655.93°C115.12V

The PSU copes nicely with high operating temperatures, without needing high airflow which translates to increase noise output. 

20-80W Load Tests

In the following tests, we measure the PSU's efficiency at loads significantly lower than 10% of its maximum capacity (the lowest load the 80 PLUS standard measures). This is important for representing when a PC is idle with power-saving features turned on.

Test12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan Speed (RPM)PSU Noise (dB[A])Temps (In/Out)PF/AC Volts
20W1.238A0.502A0.502A0.198A19.99377.106%85921.236.78°C0.842
11.989V4.981V3.289V5.044V25.9339.84°C115.15V
40W2.724A0.703A0.703A0.297A39.99178.968%85821.136.88°C0.915
11.998V4.98V3.288V5.042V50.64240.74°C115.16V
60W4.211A0.904A0.903A0.397A59.99183.393%86221.338.67°C0.937
11.997V4.98V3.288V5.04V71.93742.85°C115.15V
80W5.694A1.105A1.104A0.496A79.9386.052%86321.339.31°C0.954
11.996V4.979V3.287V5.038V92.88643.85°C115.15V

With light loads the fan spins at low speeds, so noise output remains low. 

2% or 10W Load Test

From July 2020, the ATX spec requires 70% and higher efficiency with 115V input. The applied load is only 10W for PSUs with 500W and lower capacities, while for stronger units, we dial 2% of their max-rated capacity.

12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan Speed (RPM)PSU Noise (dB[A])Temps (In/Out)PF/AC Volts
0.727A0.222A0.278A0.051A10.98767.802%82319.825.61°C0.752
11.986V4.978V3.286V5.046V16.20526.4°C115.14V

The PSU breaks the 60% barrier, it would be nice to see over 70% efficiency though, in this test. 

Efficiency & Power Factor

Next, we plotted a chart showing the PSU's efficiency at low loads and loads from 10 to 110% of its maximum rated capacity. The higher a PSU’s efficiency, the less energy goes wasted, leading to a reduced carbon footprint and lower electricity bills. The same goes for Power Factor.

At high loads, efficiency takes a big hit with 115V input. Nonetheless, still the platforms is efficient with a lower voltage input under all load conditions. We would like to see a little higher PF readings with 230V input, where most APFC converters don't performs so well. 

5VSB Efficiency

Test #5VSBDC/AC (Watts)EfficiencyPF/AC Volts
10.1A0.505W77.815%0.093
5.046V0.649W115.19V
20.25A1.261W81.308%0.189
5.045V1.551W115.19V
30.55A2.774W82.472%0.293
5.045V3.364W115.18V
41A5.043W82.758%0.359
5.044V6.094W115.17V
51.5A7.564W82.018%0.396
5.043V9.222W115.16V
62.999A15.113W79.486%0.449
5.039V19.014W115.15V

The 5VSB rail is highly efficient! 

Power Consumption In Idle And Standby

Mode12V5V3.3V5VSBWattsPF/AC Volts
Idle11.968V4.975V3.284V5.047V4.1740.392
115.14V
Standby0.0480.007
115.14V

Vampire power is low with both voltage inputs. 

Fan RPM, Delta Temperature, And Output Noise

All results are obtained between an ambient temperature of 37 to 47 degrees Celsius (98.6 to 116.6 degrees Fahrenheit).

(Image credit: Tom's Hardware)

(Image credit: Tom's Hardware)

The fan speed profile is not aggressive, even at high operating temperatures. 

The following results were obtained at 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit) ambient temperature.       

(Image credit: Tom's Hardware)

(Image credit: Tom's Hardware)

At average operating temperatures close to 30 degrees Celsius, the PSU is silent with up to 355W loads at 12V. with 440W on the same rail the PSU passes the 30 dBA mark.

MORE: Best Power Supplies

MORE: How We Test Power Supplies

MORE: All Power Supply Content

Aris Mpitziopoulos
Aris Mpitziopoulos

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

  • WrongRookie
    Is there a way to tell if it supports full range input till 240v?
    Reply
  • Tom Sunday
    Most of the PSU’s are made by a small group of manufacturers, and resellers simply buy those manufacturers PSU's and then rebrand them as their own products. I usually buy SeaSonic because pure and simple they are a manufacturer. They make all their own PSU’s and sell them to consumers. So going with a SeaSonic PSU is almost certainly to be a safe bet. I also found that resellers generally offer three to five-year warrenties on their PSU's, and Seasonic offers in many cases five to twelve-year waranties. This alone tells the story and in how much confidence the reseller usually has towards its selected manufacturer.

    In turn CORSAIR is a true reseller, not a manufacturer. This can be a big deal. They buy their PSU’s from their original manufacturers so the quality of their products ultimately depends on their original manufacturers or perhaps those manufacturers which returned the lowest fabrication bid on a large CORSAIR factory order. It can be difficult to find out where CORSAIR’s PSU’s come from as CORSAIR has routinely been using 3-5 different manufacturers and in diffrent countries. In time likes these where high wattage and or premium PSU’s (1200W-1600W) may easily exceed $400 plus to especially feed the upcoming 4000 series GPU craze, picking the right PSU becomes important! As one of the dealers at the recent computer show noted: “SeaSonic principally specializes in PSU’s while CORSAIR markets and sells hundreds of different products. “Go take your pick!”
    Reply