Since it's beginning in 1990, Enermax Technology Corporation has built a very good name for its self in the ATX power supply and case markets.  Originally based in Taiwan, Enermax has spread subsidiaries and agents to all corners of the globe.  Here in the United States, Enermax is represented by Coolergiant Computers, Inc (an Enermax susidiary).

When it comes to purchasing a quality power supply unit (PSU), Enermax usually comes up on the list.  As of late, the PSU market has been flooded with lots of new contenders like OCZ, Mushkin, Nexus, Sunbeam, and Silverstone. It has become increasingly difficult for small companies to get a leg up on the competition.  Enermax has really gotten themselves back in the game with ther Liberty series power supply units.  Available in 400W, 500W, and 620W flavors, the Liberty power supplies from Enermax all feature active power factor correction (PFC), two exceptionally powerful 12v rails, a modular cable management system, and full ATX 12V 2.2 compliance.  Today, HardwareLogic has the distinct pleasure of reviewing the SLI ready Enermax Liberty 500 watt PSU (ELT500AWT). 

Power Supply Specifications

DC Output:	+3.3v	+5V	+12V1	+12V2	-12V	+5Vsb
	28A	30A	22A	22A	0.6A	3A
	160W		384W (32A)		7.2W	15W
	477.8W				22.2W

Having full Intel ATX 12V 2.2 certification means the Enermax Liberty 500W PSU features two very powerful 12V rails (both at 22A each) and a total output peak power of 500W, which should be powerful enough to handle prettymuch any single or dual core processor and single and dual GPU setup.

In addition to a very solid spec sheet, Enermax has also managed to outfit the Liberty 500W with a very impressive list of special features!

	Enermax Specification	Additional Notes
	Full compliance with the highest standard to desktop power requirements.  Split 12V rails provide most stable current to CPU, GPU, MB, and drives.	Prettymuch an industry standard now, but still a very nice feature.
	Full support of dual core systems (incl. Pentium D EE and Athlon 64 X2) & Dual CPU systems.	Basically includes the necessary ATX 12V connections for CPU power requirements.
	Convertable design to power up ATX/BTX systems and support dual CPU entry-level server/workstations.	Although BTX is a very small part of the market, I suppose it is still something to keep in mind.
	PF value up to 0.99 to provide stable and clean power under 100-240VAC by auto switching.	Power Factor Correction (PFC) basically workes to keep the AC power waves in correct shape and be used more effectively.  Active PFC is a very good thing and a Power Factor (PF) value of 0.99 is very high (theoretical maximum is 1.0)
	High efficiency of about 80% under wide load range (30-100%) minimizes your electricity bill.	This high efficiency is no doubt aided by the active PFC but, obviously, the higher the efficiency the better.
	Special design 12cm fan combines silence and cooling by intelligent speed control.	Bigger fans move more air with less noise, so this is also a very nice feature.
	Protected by OCP, OVP, UVP, OLP, SCP, OTP for maximum safety.  Full rated power under 0-40Â�C/32-104Â�F ambient temp.	This covers things like over voltage protection, undervoltage protection.
	Smarter cable choice and better cable routing for a neat and tidy case.	This is a design feature that more and more power supplies are including.  It definately helps make cable management inside the case much easier
	Unique 4-pin Molex + SATA connectors in pairs give you free choice on using either PATA or SATA devices.	Basically Enermax just put SATA power connections and 4-pin Molex connections on the same cables.
	Support of Dual PCI-Express graphics cards, SLI or CrossFire.	There are two seperate 12V PCI-Express power cables.
	Toughest EMI shielding protects your system and near-by appliances.	Also a product of active PFC, less EMI and RFI is a good thing.

As you can see, there is a lot to like about the Enermax Liberty 500W PSU.  Lets move on and take a look at what you'll actually get when you spend your hard earned cash on one of these beauties...

Retail Box and Accessories

The Enermax Liberty 500W PSU comes packaged in a sturdy cardboard covered with colorful images, specifications, and features of the power supply inside.

Enermax actually includes a nice little accessory bundle with the Liberty power supplies.  From left to right we find a silver Enermax lanyard, a little bag with two different Enermax stickers, a fairly informative printed user manual (in six languages), a bag with four standard 6/32 thread size case screws needed to mount the PSU inside your case, another little bag with three plastic caps used to cover and protect the extra 6-pin modular connections on the back side of the PSU, and the usual power cable needed to plug the PSU into your wall socket.  To be honest, at least 50% of these items are not even necessary in order to use the Liberty PSU, but the fact that Enermax took the time and effort to include such goodies shows that they are willing to take the extra step for their customers; something that really stands out in my mind.

Physical Inspection

Probably the most pronounced physical feature on the Enermax Liberty 500W PSU is the bright gold wire fan grill protecting the fan blades on the large clear 120mm cooling fan.  The choice to fit the Liberty with a 120mm fan is a very good choice as it will provide the best air flow with the least amount of noise. 

The fan its self has clear blades with a black frame and is clearly marked for silence using a ball bearing motor.  The model is B1202512M-3M and is rated for DC12V power at 0.30A.  During testing I found this fan to be extremely quiet with only a very slight bearing noise when I put my ear right next to the fan; something that would be easily muffled by surrounding case fans and the side panels of the chassis.

The air that is pushed down onto the heatsinks and components inside the Liberty 500W is eventually passively exhausted out this rear vent.  The entire end of the PSU is made of a honeycombe design to optimize airflow.  Here we can also see the power plug and the on-off switch.  Opposite the honeycomb exhaust panel we find the real meat of the Liberty 500W PSU.  During testing I never felt this unit get overheated or even hot.  The casing and exhaust air was always very cool, signifying that the cooling system implemented works very well.

PHYSICAL INSPECTION CONTINUED

There are only two bundles of cables that are permanently attached to the Liberty 500W PSU.  One being the 20+4 pin ATX power cable and the the other bundle contains two 4-pin 12V power connctions and a 3-pin connector that can be connected to the motherboard to monitor the fan speed (RPM) of the Liberty 500W's 120mm cooling fan.

 Here we have all the modular power cable connections.  There are a total of eight modular connections (two of which being dedicated for the PCI-Express cables - in red).  We will cover the connectivity of the Enermax Liberty 500W in more detail on the next page.  Also visible in the picture above is the small black rail that runs along the bottom edge of this side of the PSU.  I am not sure of the exact purpose of this rail, but I want to make it clear that this piece of material is not removeable and adds about an extra 1cm to the outside dimensions of the unit.  In most cases, this extra piece of metal shouldn't be a problem since it is not as long as the entire width of the PSU (there is still about 1cm to spare on each side).  But if your case has a tight squeeze and extravagent housing for the PSU, you might want to keep this in mind or get your dremel cutting tool ready.

The top panel of the Enermax Liberty 500W PSU is void of any markings or vents.  One thing I did notice though is that the finish of this PSU is very nice.  The entire casing is painted up with a black gloss finish and the paint they chose happened to have small sparkles in it.  They are not easily visible and it took a few tries to get them to show up correctly in the pictures, but the sparkles are definately in there.

Finally, you can see the inside components of the Enermax Liberty 500W in the picture above.  I DO NOT recommend removing the cover on your power supply as it will void your manufacturer's warranty and put yourself in danger of severe injury or death because of the powerful electronic components inside. 
Cooling inside the Liberty 500W is handled by the two large gold colored aluminum heatsinks.  The nice thing about the modular power supplies is that the inside is very clean because of the reduced number of wires requred. 

Instead of having wires for every cable on the power supply, there is a single small PCB that houses all of the modular connections.  Less clutter and wiring inside the PSU means that cooling will be more efficient and the power supply unity will be more stable and run better. 

At the very corner of the main PCB we find that that the cooling fan is connected with a removeable 3-pin connection

Permanent Cables and Connections

As mentioned before, there are only two bundles of cables permanently attached to the Liberty 500W unit.  The top-most connection at the far left of the picture above is the 3-pin cable that the user can plug into the motherboard and monitor the speed of the cooling fan in the Liberty 500W.

In one bundle we find the 20+4 pin ATX power connector.  Depending on the motherboard you are using, the powr connection can be either 20-pin or 24-pin by simply putting the two connections together so the arrows point at each other.  While this is fairly self-explanitory and easy to use, I would have preferred the method adopted my most other PSU manufacturers where the extra 4-pin connector actually slides in next to the 20-pin connector and doesn't move.  With this set up, you have to hold it there while you plug the whole thing in.

The other bundle contains two 12v 4-pin power connections and the fan speed sensor wire we touched on earlier.  Like the 20+4 pin ATX power connection, these two 12V 4-pin connections can be put together with the arrows to form a single 12V "EPS" power connection that some newer motherboards require.

Modular Cables and Connections

Enermax was kind enough to include a suprisingly heavy-duty canvas bag for storing the selection of modular cables.

Inside the bag we find all of the modular cables nestled into their little pockets and elastic bands for safe keeping.  I think this cable storage bag is a very good idea on Enermax's part and it makes me very happy to see such an accessorty included with the Liberty power supplies.

There are a total of six seperate modular cable attachments included with the Enermax Liberty 500W PSU...

There are two 6-pin PCI-Express 12V power cables, fully sleeved with black and gold weaved cable sleeving and both measure in at about 23 inches long.  Notice the connections are red, this is so you know that you need to plug them only into one of the two red 6-pin modular connections on the Liberty unit its self.  This is something you really need to pay attention to because these PCI-Express connectors can also be plugged into the other modular cable connections.  The problem with this is that the other black colored modular connections supply different power voltages to the individual pins than the PCI-Express connections do, so you could really cause yourself some problems by plugging a red cable into a black modular connection or vise versa.  This is one thing Enermax should have done a little better job on and redesigned one of the two types of connections so you physically cannot plug one into the other.  Just pay attention and read the manual to avoid any problems.

Next up we have two more identical modular cables featuring two SATA power connectors and two 4-pin molex connectors each.  These are an example of what Enermax calls their "Eternity Pair" cables because each cable has a pair of SATA and molex power connectors.  Some may like this design while others may hate it, you really can't please everyone.  During my time working with the Liberty 500W, I had mixed feelings about the "Eternity" cables.  I think it is a good idea and might work good in some very particular situations, but I found that the connectors were a little too close together to be able to all be utilized; thus forcing you to add another cable for the longer connections and defeating the purpose of having a modular PSU.  These cables (pictured above) are only sleeved from the 6-pin modular connector to the first SATA power connector and are both about 30 inches long.

Finally, the last two modular cables included with the Liberty 500W are also twins and are still only sleaved from the 6-pin modular connector to the first SATA power connector.  They are both about 40 inches in length and feature the same two SATA power connectors and two 4-pin molex connectors, but also have the added connectivity of a floppy power type connector at the very end.
Another feature I want to point out on the Enermax Liberty 500W PSU are the 6-pin modular connections themselves...

The male and female connectors securely clip into each other.  This is nice because it prevents the cable from accidentally wriggling free or making a bad connection that could obviously cause some headaches down the road.  Speaking of connections, the 4-pin molex connectors are also worth mentioning...

I think everyone has had the pleasure of experiencing the difficulty of trying to remove a regular molex connector from a hard drive or optical drive.  Thankfully Enermax recognizes this issue and patented their own type of molex connector with a little "tab" on the top that, when pressed down, slides forward and helps make it easier to remove the connector from the device; a welcome feature indeed!

Finally, I just wanted to point out that the majority of the cables on the Enermax Liberty 500W are sleeved, helping to keep the rat's nest effect to a minimum inside your case.  Again, this is a very desireable feature and it's nice to see it included on these Liberty power supply units.

TESTING

All tests were run on the following components using Windows XP Professional SP1:

Category	Component	Notes
Processor	AMD Athlon 64 3200 Venice	Stock 200mhz x 10 speed (2.0Ghz)
Motherboard	Chaintech VNF4 Ultra	Chaintech V5.0 BIOS
RAM	OCZ Platinum PC-4800 2x512MB	200mz 1:1 with 7-2-2-2 and 1T timings
Video Card	eVGA 6600GT 128MB PCI-Express	Stock 500mhz core and 1.0Ghz memory speed  Default image quality driver settings
HDDs	Western Digital 74GB Raptor Seagate 120GB 7200.7	SATA, 10,000rpm, 8MB cache  PATA, 7200rpm, 8MB cache
Power Supply	Enermax Liberty 500W
CPU Cooling	Thermalright XP-90	Arctic Sliver 5 TIM and 92mm Panaflo Ultra Quiet FBA09A12L1BX
Other	LiteOn DVD-ROM  LiteOn 52x CD-RW  USB 2.0 42-in-1 card reader  2x12" UV CCFL tubes  2x120mm Evercool fans	Full speed (12v)

The Results

A digital multimeter was used for taking the voltage measurements from the Enermax Liberty 500W.  I chose four testing environments designed to mimic different types of real-world uses.  Idle measurements were taken at the Windows XP Professional desktop with only background services and driver utilities running (no programs).  Futuremark's 3DMark03 is an intense 3D graphics benchmark designed to stress the GPU, RAM, and CPU and be a representation of a full gaming load.  Prime95 is a program that calculates Mersenne prime numbers indefinately at 100% processor load, the small FFT test was used for testing.  The final test environment was simply playing a full screen DVD with full surround sound. 

This first chart shows the voltage output measurements from the 12v, 5v, and 3.3v rails taken directly from the 20+4 pin ATX connection of the Liberty 500W:

Examining this chart shows that the voltage rails powering the cables of the 20+4 pin ATX connection are extremely stable under every testing situation.  3DMark03 caused a slight drop in the 12v rail (down to 11.96v) because it is a very graphics intensive benchmark and the video card (a 128MB 6600GT) draws all of it's power directly from the PCI-Express x16 slot of the motherboard.  The 12v rail fluxuates no more than one third of a percent (less than 1%), the 5v rail is about 1.2% high at 5.06v, and the 3.3v rail reads (at most) about 2.1% high. 
Next up I took voltage measurements from each of the seperate modular connections to see if there were any large variations across the available connections:

After measuring every voltage rail of each single modular connector, I found that the voltage output was virtually the same regardless of what the load was on the connection.  The cable with the two hard drives and fans produced the same readings as the cable with the optical drives and front panel accessories and both cases yielded very similar results to voltages measured on the empty modular connections.  So in an effort to reduce redundancy and make this article easier to read, I averaged all of the measurements taken on each of the voltage rail from all of the modular connections to create the chart you see above.  In short, voltage measurements were extremely stable across the board.  The rails never dropped below thier rated voltage and showed very little real-time fluxuation.  The largest variation appeared again on the 3.3v rail which was 2.65% high.  I would consider these measurements to all be very stable and satisfactory.

This next chart above shows the voltage output measurements taken from the PCI-Express modular power connections.  Although the video card used for testing did not requre an extra PCI-Express power cable to stress these connections, I still wanted to show that the voltages coming out of these two connections are indeed very stable, powerful, and reliable.

Finally, this last chart shows the voltage output measurements taken from the 12V 4-pin CPU power connector on the motherboard.  Again, the same very stable output trend continues and we find that the Enermax Liberty 500W has no trouble powering an AMD Athlon64 3200 Venice based system.

Warranty and Support

Enermax products are "warranted to be free from defects in material and workmanship for a period of three (3) years from the date of purchase."  They also agree "to repair or replace the product, at its own option and at no charge, if, during the warranty period, it is returned to the nearest Enermax Technology Corporation subsidiary/agent with all shipping charges prepaid and bearing a return merchandise authorization (RMA) number, and if inspection reveals that the product is defective."

The Enermax global website offers a few different services in their "Service and Supports" page.  These services include an assortment of FAQ's based on your product category, a PSU quick install guide, a downloads section for manuals, etc., and an inquiry form in case you have any "special interests" the the products or "anything else you want to know".  You can also contact Enermax regarding sales, marketing, or technical support issues.  The USA Enermax Subsidiary is Coolergiant, and they offer a support page as well with information for an RMA request form, Frequently Asked Questions, and contact information.

Our Recommendation

From the moment I opened the box, I realized that Enermax really got down to business with the Liberty 500W as everything about it screamed "quality."  From the sleeved modular cables, and high quality durable canvas cable storage pouch to the solid, secure connections and classy glossy black and gold finish on the unit's case; I was very impressed.  As I said at the beginning of this review, the power supply market is being flooded with new companies coming out with new very high products and Enermax seemed to be slowly forgotten; but not for long.  Enermax launched themselves firmly back into the enthusiast power supply market with the Liberty series power supplies and did an incredible job of designing a totally new power supply that included everything users wanted and even threw in a little extra innovation as icing on the cake.  I am left with nothing but positive feelings about the Liberty 500W and would highly recommend it to anyone looking to build a new system with any of today's computer hardware components.

Pros:

• Modular cable management system with sleeving
• Virtually silent operation and very low thermal output
• Classy looks (gloss black paint finish and gold grill)
• Extremely stable and powerful voltage rails

Cons:

• "Eternity Pair" cables are a nice idea but I found the connectors to be too close together
• Modular cables only partially sleeved, would liked to have seen Enermax follow through with full cable sleeving