Introduction

We first received a sample of the Revolution 85+ about two months ago. Enermax was going to launch the product much earlier, but a sudden change in plans created some delays. During the past couple weeks, we've had a chance to play around with final hardware, which has been quite fun. There are some new innovations inside this PSU, and in fact the inside looks totally different from what we've seen in the past. Enermax now includes DC-to-DC circuitry to create all of the lower voltage rails, something normally done with a transformer. DC-to-DC technology is nothing new since we've already seen it in several other units, but the approach Enermax took isn't quite the same as other vendors, which we will see later. Note that some of the images for this article come from Enermax marketing, including photos of the packaging material since that wasn't ready in time for this review.

The appearance of our first sample was similar to previous tested models like the Infiniti or Galaxy. In fact, this power supply was originally going to be branded Galaxy 2 before Enermax chose the Revolution moniker. The original came in a gunmetal color with a golden fan-grille installed over the huge 135mm fan; all of that changed with the latest version, which will finally hit the market.

In typical Enermax fashion, the company equipped this power supply with a massive modular cabling system that can satisfy pretty much any need. Some critics will say that modular cables can cause problems with high-performance power supplies, but during testing Enermax still manages to reach very high efficiency with stable voltages.

The Revolution 85+ series comes in four different wattages: 850W, 950W, 1050W, and 1250W -- although the last will only be available for 230VAC (i.e. Europe). Today we will be looking at the 1050W model, the ERV1050EWT. The feature list is impressive, with six 12V rails, no-load operation (which will be important for future hybrid power GPUs), power saving modes for upcoming CPUs, high efficiency, and all outputs rated at 50°C.

The six 12V rails are each rated at 30 amps, although Enermax has almost certainly set the OCP a little higher, i.e. 35 amps. There is more than enough power to connect the most demanding graphics cards, a highly overclocked processor, plenty of hard drives, and still have room to spare. 12V1 delivers power to the 24-pin ATX connector; 12V2 powers both the 4/8-pin and 8-pin EPS connectors; 12V3 is for the first and second graphics card connectors; 12V4 handles the first 12-pin socket and peripheral sockets 1, 2, and 3; 12V5 gets the second and third 12-pin sockets; and last, 12V6 is for the fourth 12-pin socket and the remaining peripherals. The distribution is very good and nobody should experience any overloads with today's hardware. The 3.3V and 5V are both rated at only 25A, although this is still more than sufficient for modern systems. The standby 5V rail is stated at 5A, which is massive compared to many other power supplies, but it's necessary in order to comply with the EPS12V regulations in version 2.92.

Packaging and Appearance

The power supply comes in a sleek black package, with only the most important information printed in light grey on the front and sides. The back contains more information such as features and specifications. Naturally there's a large 80 PLUS Silver logo on the back, going along with the Revolution 85+ name and alerting users to the fact that this is a high efficiency power supply.

The appearance has totally changed from the pre-release model; it now comes in a rough sandblasted texture that reminds us of the Cooler Master UCP series. The fan grille is no longer gold but is instead black with a bright red plate and a red Enermax logo. The silkscreened Revolution 85+ is still on the side below the stamped arrows. As usual, the entire back is perforated to provide maximum airflow. The front (which will be inside of the chassis once the power supply is installed) has the jacks for the cable management system.

For PEG (PCI Express Graphics) connectors, Enermax uses 12-pin jacks and advertises them as being future-ready. The idea is that Enermax will be able to support new cable harness requirements with different connectors in the future while keeping the jacks the same. We have seen in the past how specifications in the industry change on a regular basis, so Enermax's approach is a nice extra and should help them keep ahead of the competition when it comes to supporting new standards.

Cables and Connectors

All of the cables are sleeved in Enermax's standard black mesh with golden threads. As mentioned on the previous page, the cable management works with different jacks on this PSU. The peripheral harnesses utilize a 5-pin port: one pin for 3.3V, 5V, and 12V with the last two for grounding. The connectors are keyed so that they can't be inserted backwards. The PEG connectors for graphics cards come from the 12-pin jacks. The six pins on the left each provide 12V; since each 12-pin connector supports two PEG connections, three 12V cables are routed to each PEG connector. The four PEG jacks and six jacks for peripherals should be more than enough for all but the most insane users.

As the graphic shows, the cables in this unit are not very long. 75cm is the longest distance between power supply and SATA or Molex connectors. This might be okay for many cases, but especially with cases where some hard drives are in the opposite corner from the PSU you will need cables longer than 75cm. The two long PEG connectors is a great idea since the user will be able to route these cables through the case. In addition, there are three more cable harnesses for graphics cards, each with two connectors (6/8-pin transformable). With eight PEG connectors plus features like the 12V rail design, this power supply is truly designed for maximum graphics setups.

The Fan

The fan is a double ball bearing model, frequently used by Enermax. The part number is RL4Z-B1352512LB-3M.

Internals

So far things have been pretty typical for a power supply review. After all, there are only so many ways to design a standard PSU chassis and provide cable harnesses. Now we come to the interesting part: the internals. Enermax did a tremendous job designing this power supply, but let's start at the beginning.

When I first saw the filtering stage, I asked the representatives at Enermax if CWT is the ODM. They responded by threatening to beat me up. ;-) Anyway, the filtering stage looks very good and has all of the necessary components. The coil sits on top of the PCB, covered with shrinking hose -- hence the similarity to CWT PSUs. Right nearby are the rectifier bridges, both without heatsinks. The PFC stage follows next and the coil is placed on a solid socket. Matsushita builds the three primary capacitors, rated for 220µF and 400V at 85°C.

Enermax is particularly proud of their transformers, since they synchronized both of them for quad forward circuitry. Two synchronized transformers will share the work equally, which makes the work more efficient. The power supply also features eight safety features such as OCP (Over Current Protection), UVP (Under Voltage Protection) for the AC part, UVP (Under Voltage Protection) for the DC part, OPP (Over Power Protection), OTP (Over Temperature Protection), SIP (Surge & Inrush Protection), and SCP (Short Circuit Protection).

This power supply uses a DC-to-DC topology, which means that the 3.3V and 5V rails do not come directly from the transformer anymore. The transformers can now be built for the sole purpose of delivering a stable 12V output. In DC-to-DC designs, so far the extra circuitry has been included on the main PCB in the secondary stage of the PSU. Enermax relocated this functionality to a sister PCB that we will describe in the next paragraph. The secondary stage in this power supply now only has to deal with the six 12V rails. The capacitors for this purpose are all made by Chemi-Con, one of the best but still affordable Japanese capacitor manufacturers.

So where are the 3.3V and 5V rails created? Let's have a look at the large sister PCB where the cable management sockets are located. The left side is where it happens. The upper part is for the 5V output and the bottom is for 3.3V. The output feeds directly into the cable harnesses, and from there on to the peripherals. Since this is done totally independent from the other 12V rails, this power supply can output 99% of its rated power on just the 12V rails, which we will verify in a moment. Other power supplies that generate the 5V and 3.3V rails from the transformer normally have problems with the voltage distribution if not loaded according to ATX-norm.

Testing with the Chroma ATE Programmable Load

Our test equipment consists of two Chroma programmable DC Loads that enable us to test power supplies with an output of up to 1500W. The biggest advantage of the Chroma DC Loads is simply the high precision it provides. It can measure differences as small as 0.001V and 0.0001A, which will provide us with best-in-class results.

When programming the Chroma with specific amounts of load calculated according to the ATX norm, we are able to load power supplies to an exact percentage. We can now show results at every specific percentage needed. To get the best overview of a power supply, we load each unit with 10%, 20%, 50%, 80%, 100%, and 110% of the specified output. This is easy to calculate for a 1000W power supply: the 10% load is 100W and 110% load is 1100W. Remember that this is the amount of power the PSU delivers; due to inefficiencies, a power supply will actually draw more power from the wall.

Note: If you would like to know more about our testing methodology, equipment, and environment, please read our PSU testing overview.

We have added an additional 10% on the highest load to see how the units perform with overload. This test will be performed in all future reviews. The overload test is performed at room temperature as well as under more stressful conditions; to ensure we are not too cruel to the power supplies, we will keep the ambient temperature at 50°C in the stress test. Experience shows that many units can stand the overload at room temperature but will experience problems with higher temperature and overload together. Only the best-built units will survive this.

The Testing Environment

There is one flaw in testing power supplies with programmable loads while trying to measure the sound pressure levels at the same time. Because the programmable loads get very loud, there is no chance of hearing the power supply on the test stand. In order to make accurate measurements of the noise levels we needed a way to separate the test unit and the programmable loads. Our solution was to build a very thick box around the unit.

We concluded that a five-layer box with a total thickness of 6" (15cm) containing two layers of wood and three layers of special foam would suffice. It is designed as a box within a box. The inner box does not touch any part of the outer box, making it difficult for acoustic noise to pass through in the form of vibration. Each box is isolated on both sides with a layer of heavy foam that is normally used to insulate engines. On the inside we have an additional layer of 4" (10cm) thick pyramidal foam on every side of the box to eliminate the acoustic waves coming from the test object as well as we can.

To ensure a completely closed system we installed the printed circuit board that the connectors of the power supply are attached to inside the anechoic room/box. In other box designs, you would need to put all the cables through the wall. Unfortunately, that would result in the inside of the box not being fully isolated anymore. Our design keeps everything that needs to be connected inside of the box and maintains isolation.

DC Output Stability and Quality

The DC output regulation is excellent with this power supply. Both the 3.3V and 5V rails have a regulation little over 2%; even at maximum loads of over 1000W, they stay just 1% under the ideal output. The standby rail has a larger regulation of around 6%, which is still within specs and seldom a cause for concern. As always, we combined all 12V rails into one graph. This time it represents six 12V rails, which is why the graph is so thick. With six rails, the various outputs will never be identical, and we measured a difference of roughly 0.15V at higher loads. Despite the spread between the 12V rails, we still get a voltage regulation of around 3%, which is a very good result.

The 3.3V and 5V output quality is okay, and the 3.3V rail is the worst we'll see from this PSU with a ripple result of 14.6mV. 12V1 has the lowest ripple with up to 17.79mV while the other 12V rails reach up to 30mV, but the overall results are similar to 12V1.

Efficiency and PFC

This efficiency graph surely does not need much explanation. The Enermax Revolution 85+ is the most efficient power supply we have tested to date. It reaches a little higher than 90% efficiency with 230VAC, but even with 120VAC it still manages to hit almost 89% efficiency. With 90VAC up to 86% efficiency is possible, which is simply amazing.

About the only negative is that you need a load of at least 200W to reach the optimal efficiency range. However, you can still get 80% efficiency with 120W to 150W (depending on input voltage), but then we don't expect anyone running a load of 150W to be interested in a 1000W PSU. Beyond the 200W mark, this power supply is more efficient than most other power supplies -- almost regardless of rating or load. The Enermax Revolution 85+ continues to improve on this result up to the peak efficiency reached at around 500W.

We were hoping for a similarly impressive power factor correction result, but it's merely the equal of the other high-end power supplies we've tested in this area. The 120VAC and 90VAC are above .99 for almost the entire test, which is good. As usual, 230VAC struggles but still starts at .964.

Temperatures, Fan Speed, and Acoustics

The high efficiency means that this power supply needs to dissipate less heat, which is icing on the cake. The temperatures on both heatsinks are so low that you could practically run this PSU fanless. Once we hit 100% load, temperatures start to increase, but we don't expect very many users to come anywhere near that point. What's interesting is that fan speed begins to ramp up faster than temperatures, and in fact the temperature graphs drop between the 80% and 100% load marks. Still, better safe than sorry. As for the exhaust temperature, it's very close to the heatsink temperatures, so the heatsinks and fan are doing a good job of getting heat out of the power supply.

As we saw in the temperature graph, fan speed begins to ramp up at around a 500W/50% load. It spins at 750 RPM up until the 50% mark, at which point fan speed ramps up linearly until the maximum 1500-1600 RPM at 100% load.

Noise levels for the first half of the graph are extremely low, but unfortunately noise increases rapidly with fan speed beyond that point. This is a real pity, since the heatsinks aren't even that hot and it certainly would be possible to run the fan at a lower speed. The starting point of 18dB(A) is not something you will even notice, and we couldn't hear any ticking noises either (something we have seen in non-PWM controlled fans). However, the final output of 29dB(A) definitely doesn't qualify as being silent. The good news is that you can use this power supply up to a load of around 800W and still have an acceptable amount of noise, which is sufficient for even triple SLI systems -- and those will create plenty of noise just from the graphics cards. Truthfully, for a unit delivering over 1100W of power, 29dB(A) is not at all something we would call a poor result.

Conclusion

Our expectations for this power supply were very high, but we are happy to say that it met its potential in every way. Beauty as always is in the eye of the beholder, but we do like the appearance of the Revolution 85+. The original sample was far more conservative in its design, and when Enermax told us they were revising the look we didn't think it was necessary, since it would probably just increase the price. However, we have to say that the final result does look really cool. The combination of the black textured surface with the red highlights around the fan grille is very attractive in our opinion.

The feature list is similarly impressive, even though most users will not see or recognize some of the innovations. Enermax included a lot of new technologies in this power supply, and the results are very good. It starts with a good topology that lets the two transformers act in synchronization. Another nice feature is the DC-to-DC circuitry that increases efficiency. The not new but still good addition of the 12-pin sockets on the front of the power supply give potential support for future connector developments -- provided of course that the voltage requirements don't change.

The length of the ATX and PEG cables is long enough for most systems. However, if you want to install this power supply in a case where the PSU is in the top rear and the hard drives are in the bottom front, you may have some difficulties getting the cables to reach. Likewise, if the PSU sits in the bottom of your case you might not be able to route all of the cables nicely through the chassis but will have to take a more direct path. The eight 6/8-pin PEG connectors are very nice and make this power supply ready for any GPU configuration all the way up to triple SLI and more. If you're going to use multiple graphics cards, this PSU will likely work best in a bottom-mounted location.

Build quality has never been a concern with Enermax products. About the only problem we've ever encountered were some incompatibilities in the past with a few specific motherboards. Those issues never occurred with higher end PSUs, however, and the Revolution 85+ is clearly the highest of their high-end power supplies. They have included all of the best features from their previous offerings, plus a few new ones for good measure. All of this adds up to the tremendous performance we saw today.

Voltage regulation was good and not even our 10% overload test could cause this unit to sweat. The efficiency is the best we have seen from any previous power supply to date. Enermax states on the package that up to 90% efficiency is possible, and we achieved exactly that with 230VAC. Even with a lower 120VAC input, efficiency still reached an incredible 88%. As mentioned, optimal efficiency generally requires a minimum load of 200W; if you have a system that idles above 200W, you won't need to worry about power supply efficiency for a long time.

Another nice feature is the no load function. As we hinted at earlier, we loaded the power supply using only the 12V rails, keeping the lower voltage 3.3V and 5V rails load-less. We had no trouble at all pulling up to 1000W on the 12V rails without any lower voltage rails, and the PSU still maintained a very nice regulation of just a few millivolts under 12.00V. Of course, with a DC-to-DC circuit the power supply has no total combined power anymore. For reference, when we tried this test on other power supplies, they immediately shut down when either the 3.3V or the 5V rail didn't have any load.

The heatsinks stayed very cool during testing, with temperatures lower than 40°C. Only after running at 110% for a longer period of time did we manage to get heatsink temperatures above 40°C. The fan speed begins increasing with 500W of load and actually lowers temperatures slightly for a while; it's only from 1050W onwards that the heatsink temperatures rise again and the fan can't quite keep up. The drawback is that noise levels are slightly higher than the temperatures warrant; we measured only 29dB(A) under highest load which is still an extraordinary result, but it should have been possible to keep noise levels down even further since the heatsinks aren't that hot at all. Still, it's always better to have a cooler running power supply than to toe the line, which is why Enermax regulates temperatures and fan speeds in this fashion. Keeping the internals at around 40°C at all times is not at all a bad approach, and this should increase the lifespan for this power supply.

Let's compare this unit to other 1000W units and see where it fits. Let's start with the Cooler Master UCP, since there are similarities with the Enermax Revolution 85+. The Revolution 85+ comes with about the same amount of cables and connectors. The PEG connection options are similar but the UCP has them further from the PSU, which is better for users since that provides for better cable routing options. However, Enermax has six 6/8-pin PEG connectors, giving the user greater flexibility. The Corsair HX1000W is also very similar. Compared to units from our 1000W roundup last year, the Enermax Revolution 85+ outperforms all of them. There are more connectors on power supplies now, since manufacturers have discovered that they have plenty of headroom. Power supplies also sport 6/8-pin connectors as well rather than just providing 6-pin PEG, which is a good addition.

In voltage distribution, we don't see really much difference between the Revolution 85+ and many of the competing units tested this year. The Corsair HX1000W has a very good regulation as well, so the Enermax unit has no advantage in this regard. However, when it comes to efficiency there's not much to compare -- after all, we already said the Revolution 85+ is the most efficient power supply we have tested to date. The HX1000W achieves up to 86% and the Cooler Master UCP is close with up to 89% efficiency. This brings Cooler Master back into the game, but if we compare all the additional features (i.e. safety and protection) Enermax leaps ahead again.

The final comparison is pricing. Since each "revolutionary" product that enters the market is usually more expensive than the preceding units, we are not expecting wonders here. We'll let the numbers do the talking:

As expected the MSRP for both units we listed is far above everyone else in the U.S. The Corsair HX1000W is similarly equipped with connectors and offers a wide range of features as well. For a price of around $240 it is a true bargain compared to the others in the list. Still, the Enermax Revolution 85+ offers more and we need to keep in mind that we are using MSRP for now -- street prices will almost certainly be lower. In Europe OCZ sells its EliteXStream for an extremely low price of only 140€, but the others all come close to the Enermax MSRP. Prices should also drop as availability improves, though Enermax will keep it above a certain level as we have seen with the Galaxy series. Enermax knows its advantages over the competition and that will result in prices that should stabilize slightly higher than competing products.

Even though these power supplies are anything but cheap, we are confident in making the statement that the Enermax Revolution 85+ is currently the most advanced consumer power supply available. It offers exceptional efficiency, voltage regulation, temperatures, and has very good build quality. It doesn't necessarily surpass the competition in every area, but it's always at the top of the charts. Ultimately, the innovations, feature set, and performance impress us so much that we are pleased to award the Enermax Revolution 85+ our Gold Editors' Choice Award. It's entirely possible that if you purchase the 1050W model, you could end up running the same PSU for the next couple of presidential elections -- and you can do so knowing your PC will be as green as a hybrid SUV.