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Review: Fractal Design Edison M 750W

by Tarinder Sandhu on 28 January 2015, 16:00

Tags: Fractal Design

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Testing results

Our Chroma load-testing procedures can be found at this link.


Load 10% 25% 50% 75% 100%
Efficiency 84.6% 91% 93.2% 90.6% 89.2%

Efficiency is very good across a wide range of loads. One would need to invest in significantly more expensive supplies - 80 PLUS Platinum, for example - to gain a percentage point here or there. Really, the hugely diminishing returns make 80 PLUS Gold the best value-to-performance supplies available.


In terms of regulation, we're looking at just how well the supply is able to hold to the various lines. The ATX spec. has a +/- 5 per cent leeway on all but the -12V line.

Line/Load 3.3V 5V 12V
10 per cent +0.5% +1% +1.3%
50 per cent +0.2% +0.6% +0.7%
100 per cent -1.4% -0.5% -0.5%

If efficiency is very good, regulation is simply excellent, with the Seasonic platform coming up trumps. There's a worst-case scenario of just 1.9 per cent variation on the 3.3V line.

Regulation - cross-load

How about providing uneven loads that stress particular voltage rails? In the first attempt, we've put 60A on the 12V rails, and 1A on the 3.3V and 5V rails. This can actually be somewhat typical for a system heavy on graphics and CPU power. In the second, we've turned the tables and gone for 10A on both the 3.3V and 5V rails - highly unlikely in a real-world environment - and just 2A on the 12V - even more unlikely.

Line/Load 3.3V 5V 12V
Cross-load 12V focus +1.6% +1.0% -0.6%
Cross-load 3.3V/5V focus -1.6% -1.5% +1.3%

Excellent is the word we'd use once again, particularly with the 80 PLUS Gold and sub-£90 price point in mind. The numbers are very close to the EVGA SuperNova G2 - a supply that's about as good as Gold-rated PSUs get.


Line/Load (mv - p-p max) 3.3V 5V 12V
10 per cent 10mV 10mV 20mV
50 per cent 15mV 20mV 20mV
100 per cent 20mV 25mV 30mV

The ATX v2.2 spec states that the maximum permissible ripple is 120mV for the 12V line and 50mV for others.

PSUs convert AC power into DC, but doing so requires the AC waveform to be suppressed. What we're really testing here is the quality of the supply's rectifier and any smoothing capacitors in getting rid of this unwanted up-and-down ripple. Seasonic's top-class engineering is in evidence again.


Temperatures Intake Exhaust
10 per cent 30°C 37°C
50 per cent 37°C 46°C
100 per cent 39°C 45°C

Fan performance

Temps are good but they mean little in isolation. Obtaining accurate noise readings is near-on impossible when the supply is connected to the Chroma test harness and dual-unit load-tester. We can test the manufacturer's quietness claims in a different way, by using an AMPROBE TMA10A anemometer placed directly over the centre of the PSU. The anemometer records the airflow being pushed/pulled from the PSU's fan. We can use a Voltcraft DT-10L RPM meter to measure the rotational speed of the fan, too.

Load Fan RPM Airflow Noise
10 per cent 600rpm circa-20cfm Very quiet
50 per cent 650rpm circa-20cfm Very quiet
100 per cent 2,150rpm circa-70cfm Noticeable

The Ong Hua spinner cannot be heard when a modern system is in idle mode or even when running at 375W DC. Appreciating that our Core i7 test systems equipped with a high-end GeForce GTX 980 never touch this figure at the wall - the AC value being higher than the internal DC load - the Edison M is a good choice for those who want both high performance and quiet computing.

Performance numbers are, as you would expect, very handsome.