Enermax Liberty 620w Modular ATX PSU Page: 1

Introduced almost 2 years ago, the modular power supply design was a great hit among case modders and those who took pride in keeping their PC cases tidy. Since then the modular design has had time to mature, and higher wattage units have been released into the market.

Today I'll be taking a look at the Liberty 620w modular unit from Enermax. This power supply is actually one of the highest rated modular units available on the market at the moment, and being an avid case modder myself I am highly interested in how this unit performs.

About Enermax

"Enermax Technology Corporation was founded in1990 by a group of young professional, enthusiastic, and high-tech oriented people in Taiwan . The Enermax founders left high-profile positions from prestigious computer firms, bringing over 10 years of professional experiences to our own firm.

All materials and components are tested at each stage of production. We also conduct random checks on products before and after packaging, and product inspection before delivery. Our QC and testing equipments are mostly imported from Japan."


Everybody has heard of Enermax, so it's no surprise that they have decided to keep the packaging on the Liberty series nice and plain and just let their name do to the talking.

I have to admit really liking the silver and white colour scheme of the packing which, in my opinion looks fresh and professional.

Liberty 620w Box Liberty 620w Box

Liberty 620w Box Liberty 620w Box

The front and top of the packing show a picture of the liberty in all its glory, along with some basic features of the unit. Also placed on the front of the box is a holographic sticker showing that the unit is rated at 620w and is complete with PCI-Express connectors.

On the side of the box Enermax have placed a label containing some more detailed information about the Liberty. Here we can see that the unit has a total of 6 rails, 2 of which are +12v rails, each rated at 22 amps, with a combined output of 36 amps. The +3.3v and +5v rails are also well endowed, coming in at 28 and 32 amps respectively.

Liberty 620w Box Liberty 620w Cable

Included in the box are the following items:

- Enermax Liberty manual
- Power cable
- ATX case screws
- Enermax sticker
- Enermax velcro pouch containing modular cables
- Enermax Liberty 620w PSU

Enermax have paid special attention to packaging the power supply in an attempt prevent any damage coming to its paintwork. The unit is contained within a cardboard sleeve and placed in a bubble-wrap bag which should prevent most knocks and scratches.

A nice addition to the Liberty package is the velcro pouch which contains all of your modular cables. The only down side is that the pouch isn't really suitable for any other purposes. It would have been nice if the pouch could have been used to store cd's or some of your screwdrivers.

Enermax Liberty 620w Modular ATX PSU Page: 2

The following information has been taken directly from Enermax's Website:

"Enermax® Liberty series power supply is for those who still live in a cave PCI-Express video card and CPU reaching near 4G require a new standard in power supply design. It is a modular power supply and come with a cable management sytem."

Liberty Liberty Liberty

Liberty Liberty Liberty


Enermax Liberty 620w Modular ATX PSU Page: 3

Sprayed in a jet black gloss complete with gold metallic flakes, the Enermax Liberty doesn't look like your average power supply. To get the best effect from the Liberty's paint job you definitely need to have it near bright lights, as in lower light conditions the metallic flakes are not very visible. The overall finish of the Liberty is very good, but not on par with the paintwork you'd see on a car. As you can see in the pictures below, it does have an 'orange-peel' effect to it.

Liberty 620w Front Liberty 620w Top

As with just about all power supplies that make use of a 120mm fan, the Liberty has a honeycomb mesh front which allows for the hot air passed over the components by the fan to exit out the back of your case. We can also see by the lack of a voltage selection switch that the Liberty PSU is able to auto detect the input voltage and switch accordingly.

The 120mm fan mounted in the top of the unit is protected by a gold fan grill which sports the Enermax logo. Personally I like gold fan grills and believe it to go well with the rest of the power supply, but I can imagine readers having a big divide on this opinion.

Liberty 620w Side Liberty 620w Side

The most disappointing thing about all good looking power supplies, is that the only side visible from inside your case is the very same side covered with a large specifications sticker. It would have been nice if Enermax could have placed the sticker around the other side and made the side with the embossed Enermax logo visible.

Liberty 620w Back Liberty 620w Back

The back of the Liberty sports 8 modular power connectors, 2 of which are dedicated to providing power to PCI-Express cards. Like many other modular units, Enermax have decided not to make the ATX and P4/EPS power cables modular.

Enermax Liberty 620w Modular ATX PSU Page: 4

All cables on the Enermax Liberty are sleeved in gold and black mesh which is a welcome break from the usual plain black mesh, and also fits in with the colour scheme of the PSU. The only thing that I found slightly disappointing was that Enermax did not choose to sleeve every cable right up to the connector, which left a lot of bare cables on show.

Liberty 620w Cables Liberty 620w Cables

In a change from the normal cable layout, Enermax have placed both Molex and SATA connectors on the same cable. Personally I'm not keen on this idea as it means you are more than likely to be left with lots of unused connectors on each cable. I'd be interested to find out why Enermax decided to go with this system, which they call 'Eternity'.

Liberty 620w Cables Liberty 620w Cables

Liberty 620w Cables Liberty 620w Cables

As with most modern Power Supplies, the ATX connector can be split or joined together to form either a 20-Pin or 24-Pin connector. The same goes for the P4-12v connector, which can be split or joined together to form either 4-Pin or an 8-Pin connector.

Also included is a 3-pin fan cable which can be connected to one of your motherboard's fan headers to obtain a readout of the power supply fan RPM.

Cable Cable Cable

Cable Cable Cable

With a total of 10 SATA and Molex connectors, the Liberty 620w is the best equipped power supply I've reviewed to date. I'll be surprised if Liberty owners use anywhere near the full number of provided connectors with this power supply.

Enermax Liberty 620w Modular ATX PSU Page: 5
Looking Inside

As with all power supplies that pass through Overclock3D, I'll be taking a look inside the Liberty. By doing this I should be able to get a good idea of the overall build quality of the unit and how it is likely to perform in our tests.

Liberty 620w Insides Liberty 620w Insides

Liberty 620w Insides Liberty 620w Insides

Keeping in theme with the rest of the unit, Enermax have also colour coded the aluminium heatsinks gold. The heatsinks are actually quite small, but the large number of fins should be fairly effective in drawing the heat away from the components.

The internal components are of a reasonable size, but do not occupy the entire unit. This can be the sign of a manufacturer using insufficient quality components, but as I've seen on some other makes of power supply, this is not always the case. As the saying goes "the proof of the pudding is in the tasting", so we'll see how the Liberty performs over the next page.

I'm always on the lookout for adjustable pots in PSU's that pass through OC3D, as these can come in very handy on increasing the voltages if they droop under heavy load. Unfortunately I was unable to find any on the Liberty, which is a great shame - let's hope they are not needed.

Liberty 620w Fan Liberty 620w Fan

A quick search of the internet reveals that Enermax have utilised a 120mm fan manufactured by Globefan. This fan is capable of pushing 81cfm at 39dBA whilst running at 2400RPM. Luckily, Enermax have implemented a fan speed controller into the Liberty series, which means that the fan will run much slower (and quieter) under low/medium loads.

Enermax Liberty 620w Modular ATX PSU Page: 6
Load Testing

In order for the results from all current and future PSU reviews to remain fair and comparable, Overclock3D uses a custom built Power Supply load stress tester.

The tester will be placing the following loads on each of the Liberty 620w rails:

+3.3v - 20a Load
+5.0v - 20a Load
+12v1 - 20a Load
+12v2 - 10a Load

The results are collected from a Mastech MAS-345 Multimeter which logs its readings via RS232 to a PC.

Liberty 620w 3.3v Rail Liberty 620w 5v Rail

Liberty 620w 12v1 Rail Liberty 620w 12v2 Rail

As we can see from above, all rails were fairly stable, with the most noticeable fluctuation occurring on the +5v rail. Despite this, the rail remained well within ATX specifications.

Both of the +12v rails dipped by around 0.20v taking them down to around 11.9v. While this wouldn't cause any problems what so ever, this is the kind of situation where adjustable potentiometers could have come in handy to increase the rails back up within the 12.0v mark.

Efficiency Testing

Efficiency tests are performed by measuring the wattage consumed by the power supply at the mains against the power (in watts) consumed by the OC3D power supply stress tester.

The results may not be as accurate as those produced by professional testing equipment, but will certainly come in handy when comparing several power supplies against each other.

Liberty 620w Efficiency

The Liberty 620w was placed under a load of 526 watts. This counts for a total of 85% of the power supplies rated output. At this load, the power supply required 638 watts from the mains to produce the 526 watts required by our custom made power supply tester.

Therefore the efficiency of this power supply can be found by a simple equation: (526 / 638) * 100 that works out to be an efficiency rating of 82.4%, which is very close to the 80% efficiency rating given by Enermax.

Noise Testing

Cooling the Liberty 620w is a 120mm fan manufactured by Globefan. This fan is rated at 39dBA when running at full speed which may give the impression that this unit is going to be quite noisy.

However, under idle conditions the fan is whisper quiet, and only audible if you have the unit close to your ear. With the unit installed inside a standard pc case, I was unable to hear the unit at all.

Under heavy load conditions the Liberty steps up the fan speed significantly. This does cause an increase in noise, but not to the point where it becomes an irritation. I'd estimate the noise output under load to be around 25dBA.

Enermax Liberty 620w Modular ATX PSU Page: 7

With more and more modular power supplies entering the market, it is hard to come up with something that separates itself from the pack. Enermax have certainly managed this with the Liberty, by not only making one of the highest power modular units on the market but by also making it stand out with looks as well.

In terms of performance, the Liberty fairs quite well with rails staying well within ATX specification even when placed under extremely high load. The unit also manages a good efficiency rating of 82% which should help save on some of those electricity bills.

The Enermax Liberty 620w can be purchased from SpecialTech for £99.85, which places it in direct competition with other modular 500-600w units available on the market.

+ Metallic paintwork
+ Rails suitable for SLI/Crossfire
+ Lots of connectors
+ Reasonable noise levels under full load

- Gold may not appeal to everyone
- Eternity cable system may not suit everyone
- No adjustable pots


Thanks to Enermax for providing this sample for review.

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