Original Link: http://www.anandtech.com/show/2324


Enermax is another manufacturer that has been in the market already for quite a few years now. In fact, Enermax was the first company to release major retail products, and they actually introduced the first color painted power supply to the market. Enermax as a company has been at the forefront of introducing new technologies and conforming to the latest ATX specifications. Their tight relations with companies like Intel, AMD, and NVIDIA certainly help in this regard.

Today we have the latest model from Enermax: the Infiniti series in its 650W version. The Infiniti series was introduced about a year ago and we saw early samples in Taipei at that time. We were surprised by the high efficiency of the Infiniti when we first had a chance to look at one, and now we finally can review a shipping retail unit. Enermax has also added another new technology with this PSU called CoolGuard.

The label shows three 12V rails, two with 28A and the third with 30A. The lower voltage rails are similarly rated and don't differ much from previously tested power supplies. With the three 12V rails Enermax has taken a different approach to the limited amperes problem than other manufacturers. We have mentioned this before in reviews of single 12V rail power supplies, where some manufacturers have tried to solve the problem of important 12V rails not delivering enough power in high-end system by having a single high amperage 12V rail. With 28A and 30A Enermax has a better approach, since there are currently no components that wouldn't be satisfied with 336W or 360W. Even better is that Enermax lists the real combined 12V amperage (52A), so while each 12V on its own is capable of delivering a decent amount of power, the total between the three rails is less than their sum. Enermax's OCP is around 32A to 34 amps in most cases, even though they list 28A on the label for two of the rails.

CoolGuard and PowerGuard

CoolGuard is a newly invented function Enermax has implemented in the Infiniti series. Similar functions have already been available on the market for a while from other manufactures, but the idea is that CoolGuard runs the installed fans in the system for a short time even after the PC is shut down. The problem Enermax is addressing is the lack of cooling after PCs are turned off. The fans are turned off with the system but components like the CPU and GPU can still be quite hot. In some cases, with no fans moving a system might even heat up slightly after shut down. According to Enermax the CoolGuard function will lengthen the life expectancy of the components through a better cooling even after the system is turned off. Depending on PSU temperature, the fans will continue to run for anywhere from ten seconds to two minutes.

A little LED on the backside of the PSU shows if the PSU is working correctly or has experienced a failure. During testing we have indeed verified this feature works; under high temperatures of 50°C we managed to get the red light to activate and we were greeted with two beeps repeated at regular intervals, which means that the PSU has shut down to prevent overheating.

Packaging and Appearance

The Infiniti power supply comes in a big box with enough space for all the accessories. Since Enermax is mostly focused on the enthusiast retail market, we are greeted with several extras for the customers like a lanyard, stickers, and silicone covers for unused cable sockets. There is also a splitter cord in the box for two floppy drives that can be connected to a normal Molex connector. Of course there is also the usual stuff like a power cord, manual, and a small bag that can be used to store extra cables. Our power supply wasn't covered in bubble wrap, but there's enough space and padding on all sides that the PSU should be relatively safe from any damage that could occur during transport.

The Infiniti comes in a nice brushed finish with a copper/titanium-like color. The huge 13.5cm fan has a golden fan grille that makes a very good first impression (if you care about looks). The rear of the PSU that will serve as the exhaust when the unit is installed is perforated on the entire surface. Enermax uses hexagonal shaped holes which seem to be the best solution in terms of noise, airflow, and rigidity while still being small enough to prevent EMI issues.

Cables and Connectors

All cables are sleeved in a black mesh with golden stripes up to the first connector. As we have stated before, we totally understand this approach because the higher cost of putting sleeving between each of the connectors doesn't generally provide enough benefit to be meaningful. Enermax was the first company to introduce the new 8-pin PEG connector with the Infiniti line in 2006.

There are in total eight jacks to which cables can be connected. The two red jacks are reserved for the PEG cables and the black ones are for all other components. A closer look shows the difference between the jacks extends beyond the color. The upper right pin is closed to prevent the user from accidentally connecting the wrong cable. Similarly, it is not possible to connect a normal peripheral cable to the PEG jacks since the shape of the pins doesn't match. The cables have a very snug fit when installed, which is necessary to reduce the resistance which is generated by the additional separation from the cables.

With a maximum length of 80cm the Infiniti has very reasonable cables. All the major connectors such as ATX, 4-pin and PEG have a length of 50 cm which is above average. With up to nine Molex and six SATA connectors users will have the chance to connect quite a few additional components. Also note that the two 6-pin PEG connectors have an additional connection on the PSU side that can be used to create an 8-pin PEG connector for the latest graphics cards. With an additional cable (EMC009) which you can buy in the shops you can even assemble another 6/8pin PEG connector.

The Fan

The 13.5cm fan is transparent and fits in perfectly with the overall appearance of the power supply. Enermax recently acquired a company in China that now helps with the production of fans, among other things. However, the UL number on the fan belongs to Globefan, a company that produces fans for many other power supply manufacturer as well.


Opening the power supply, we are greeted with a nicely arranged interior. The filtering stage is actually located on an extra PCB directly in front of exhaust area (at the right in the above image). A nice detail is that the small PCB is not the same length/height as the main PCB; this means that air will be able to circulate under the main PCB and potentially provide better cooling. The design also means that unlike other designs (i.e. the Zippy Serene), no components are hindering air from coming through, potentially causing some turbulence.

The PFC stage contains the main cap from Hitachi rated at 390µF and 400V. The rectifier bridge also gets an extra little golden heatsink.

The secondary side looks a little crowded, which is a pretty common trait with many other power supplies as well. Most of the cables block the airflow, limiting the ability of the fan to cool components in this area.

All the safety features are supplied by a small chip sitting on a PCB near the cables; this chip is from the Taiwanese company Silicon Touch Technologies, which is the same as most other Enermax PSUs. It works fine and we haven't encountered problems with it so far.

Test Setup

As usual we are testing with our Chroma programmable loads to fully load each rail to a specific amount. This is important to get truly accurate results and not merely approximate values. The tests are conducted in two different temperature environments. One is a normal room temperature of 25-26°C, while the second environment goes from room temperature and increases steadily up to 50°C. Especially during the higher temperatures we will see how good the power supplies are and what they're really made of. Components inside will perform much worse at higher temperatures, but we expect any good quality PSU to deal with such test conditions without failing.

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

PSU Rail Loading
PSU Load 3.3V 5V 12V1 12V2 12V3 Wattage
All Rails
10% 1.40A 1.68A 1.38A 1.38A 1.48A 67W
30% 4.20A 5.04A 4.13A 4.13A 4.43A 200W
50% 7.00A 8.40A 6.89A 6.89A 7.38A 331W
80% 11.20A 13.44A 11.02A 11.02A 11.81A 525W
100% 14.00A 16.80A 13.77A 13.77A 14.76A 651W

The lower voltage rails remain very nicely inside specs. The standby rail starts a little on the high side with about 5.17V, but that's no problem at all. No rail even came close to the lower limits.

Simply stated, Enermax has very high voltages on the 12V rails. As can be seen, the test starts at around 12.39V which is quite high (though technically within specs). Since the output starts so high, the drop as load increases doesn't even bring the voltage under 12.00V and only in the case of the 12V3 rail did we actually see the voltage dropping close that amount. One year ago we tested a first sample of an Infiniti 720W version on a Chroma 8000. A report can be downloaded here for comparison. At that time we were already recording similarly high voltages on the 12V rails, and this obviously continued into mass production.

Standby Efficiency

Standby Efficiency - 115VAC

Standby Efficiency - 230VAC

The standby efficiency looks very good and even with 230VAC we see a decent result. Enermax seems to have a very good topology here since we have better standby efficiency than the previously tested Zippy Serene.


We are surprised (and pleased) to see that the efficiency is equal to what we first saw with the first pre-production sample a year ago. We are reaching 86% efficiency under best conditions and even in our stress scenario at 50°C we still measure efficiency results of more than 80%. For loads of between 175~550W, the efficiency will be above 80% regardless of input voltage.


Unfortunately the PFC again doesn't perform that well, particularly with higher input voltage such as 230VAC. Buyers in the US can be happy about a very good correction factor but the guys in Europe will have to live with slightly lower rates of up to 0.985.


While testing the Infiniti we encountered some very strange behavior in regards to temperatures. The exhaust temperature was similar at the various loads throughout testing, whether at room temperature or in the heat chamber. The secondary heatsink also stays at almost the same temperature in both environments, which means the power supply is not really dependant on the ambient temperature. Only the primary heatsink shows any significant changes in our heat chamber. At room temperature, it was only a few degrees higher than the ambient temperature; this pattern holds in the heat chamber as well, where it remains just a few degrees above ambient topping out at ~53°C. Needless to say, the temperature results are quite impressive.

Fan Speed

The fan behaves more like it's dependent on the load of the power supply rather than the temperature of the inside. The fan reached a maximum of 1500 RPM in our heat chamber before the safety feature kicked in to prevent overheating. While the room temperature was constant, the fan speeds up at higher loads in order to deal with the higher inner temperatures.


Even though the fan stays at a relatively low RPM level, the noise levels rise quite a bit, especially during the heat chamber test. We measure noise levels that are over 10dB(A) higher under heavy stress conditions than at room temperature. That means the fan really starts to make some serious noise at full speed. At the highest speed the fan is clearly recognizable since it produces 40dB(A) of noise at a one meter distance. On the other hand, in more comfortable operating environments the maximum 29dB(A) was hardly noticeable and not at all annoying. The larger fan with low RPMs does create some wind noise, but it is at a frequency that we did not find distracting and we would say subjectively the PSU is close to silent when operated at room temperatures.

After 20 minutes in our 50°C heat chamber, the Infiniti shut down with a clearly audible beep. Enermax states quite clearly that they prefer to have the PSU survive instead of burning up at high temperatures. We think the fan could spin a little faster than just 1500 RPM to help cope with the added heat (which of course would mean more noise) but that wasn't the case. One thing we might like is to get some warning beeps indicating that the PSU is about to overheat, thereby giving users an opportunity to save any critical documents and shut down gracefully rather than having the over temperature protection kick in. A hard shut down might save the PSU, but such actions aren't without potential side effects.


It is clear that the Infiniti is at the moment the best power supply in the Enermax portfolio. It has pretty much everything a user could wish for. The focus of the Infiniti is definitely not the mainstream market but more the high-end enthusiasts. We intentionally tested the 650W version of the Infiniti, since we wanted to show what the lower performing version can provide. A 720W version is also available, but for many users that would simply be overkill. The build quality is very good and Enermax takes no chances with low quality components. The case of the PSU comes with a nice looking brushed exterior, and in combination with the golden fan grille this will be an eye catcher in store displays and possibly inside your PC.

Efficiency Comparison

From the efficiency point of view, the Enermax Infiniti is playing in the top ranks of our comparison list which shows the highest measured efficiency of each unit we have tested so far. Indeed, the Infiniti has a very good efficiency rating over the whole range of input voltages. At most loads it remains above 80%.

Efficiency Comparison

Whoever buys an Enermax PSU can also rest assured that they will have enough cables and connectors for just about any conceivable configuration. Enermax is a company that pays attention to detail, and they don't skimp on the extras. As already stated, Enermax was also the first company to provide PSUs with 8-pin PEG connectors on a retail product, long before much of the competition. The Infiniti comes with three 6-pin PEG connectors, one of which is transformable to an 8-pin PEG connector. This is definitely nice for a 650W power supply.

The inside seems to be nicely arranged but we do feel strange about the similar temperatures with any kind of ambient heat. The heatsinks have a decent size and it's good to see that secondary heatsink is bigger than the less warm primary one. The air still has enough space to slip through to the PCB on all sides of the heatsinks which will provide the other components with a little cooling air.

The DC output has been very stable and no rails even went close to being out of specification. The 12V rails in particular are consistently very high with loads of up to 300W, and they never go lower than 12.05V.

Since the Infiniti has been available for a year now, the prices are quite stable. You can get this 650W PSU for about $190 plus shipping in the US. The cheapest price in Europe is about €140 which equals the $190 price in the US. For a 650W power supply the price is definitely not cheap, and users will need to decide if the package offers enough value to warrant a purchase. There are surely other power supplies with similar quality, fewer unnecessary accessories, and a lower price. If saving a Jefferson or two isn't high on your list of priorities, however, the Enermax Infiniti is a good quality offering.

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