Enermax NAXN 80+ 600 W Power Supply Review

[nextpage title=”Introduction”]

The NAXN, the latest power supply series from Enermax, is subdivided into three sub-series: the NAXN, also known as Tomahawk II, featuring 350 W, 450 W, and 500 W models, with no 80 Plus certification; the NAXN 80+, featuring 350 W, 450 W, 500 W, and 600 W models, with the standard 80 Plus certification; and the NAXN 82+, featuring 750 W and 850 W models, with the 80 Plus Bronze certification and modular cabling system (a feature not available on the models from the other two sub-series.) Let’s see if the new Enermax NAXN 80+ 600 W is a good option.

While Enermax has its own factories, the NAXN 80+ 600 W is actually manufactured by CWT, and uses the same platform as the Corsair CX series.

Figure 1: Enermax NAXN 80+ 600 W power supply

Figure 2: Enermax NAXN 80+ 600 W power supply

The Enermax NAXN 80+ 600 W is 5.5” (140 mm) deep, using a 120 mm sleeve bearing fan on its bottom (Yate Loon D12SH-12, maximum of 2,200 rpm, 88 cfm, and 40 dBA). 

This unit doesn’t have a modular cabling system. This power supply comes with the following cables:

• Main motherboard cable with a 20/24-pin connector, 19.7” (50 cm) long
• One cable with two ATX12V connectors that together form an EPS12V connector, 24” (61 cm) long
• Two cables, each with one six/eight-pin connector for video cards, 20.5” (52 cm) long
• One cable with four SATA power connectors, 18.9” (48 cm) to the first connector, 5.9” (15 cm) between connectors
• One cable with three SATA power connectors and one standard peripheral power connector, 18.9” (48 cm) to the first connector, 5.9” (15 cm) between connectors
• One cable with three standard peripheral power connectors and one floppy disk drive power connector, 18.9” (48 cm) to the first connector, 5.9” (15 cm) between connectors

All wires are 18 AWG, which is the correct gauge to be used.

The cable configuration is very good for a 600 W product, with a total of seven SATA power connectors.

Figure 3: Cables

Let’s now take an in-depth look inside this power supply.

[nextpage title=”A Look Inside the Enermax NAXN 80+ 600 W”]

We decided to disassemble this power supply to see what it looks like inside, how it is designed, and what components are used. Please read our Anatomy of Switching Power Supplies tutorial to understand how a power supply works and to compare this power supply to others.

On this page we will have an overall look, and then in the following pages we will discuss in detail the quality and ratings of the components used. As already explained, this power supply uses the same platform as the Corsair CX series.

Figure 4: Top view

Figure 5: Front quarter view

Figure 6: Rear quarter view

Figure 7: The printed circuit board

[nextpage title=”Transient Filtering Stage”]

As we have mentioned in other articles and reviews, the first place we look when opening a power supply for a hint about its quality, is its filtering stage. The recommended components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components, usually removing the MOV and the first coil. 

In this power supply, this stage is flawless. It has one X capacitor and two Y capacitors more than the minimum required.

Figure 8: Transient filtering stage (part 1)

Figure 9: Transient filtering stage (part 2)

In the next page we will have a more detailed discussion about the components used in the Enermax NAXN 80+ 600 W.

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the primary stage of the Enermax NAXN 80+ 600 W. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one GBU1006 rectifying bridge in its primary, which is attached to an individual heatsink. This bridge supports up to 10 A at 100° C, so in theory, you would be able to pull up to 1,150 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 920 W without burning itself out. Of course, we are only talking about this particular component. The real limit will depend on all the components combined in this power supply.

Figure 10: Rectifying bridge

The active PFC circuit uses two MDF18N50 MOSFETs, each one supporting up to 18 A at 25° C or 11 A at 100° C in continuous mode (note the difference temperature makes), or up to 72 A at 25° C in pulse mode. This transistor presents a 270 mΩ resistance when turned on, a characteristic called RDS(on). The lower this number the better, meaning that the transistor will waste less power, and the power supply will have a higher efficiency.

Figure 11: Active PFC transistors and diode

The electrolytic capacitor that filters the output of the active PFC circuit is from Samxon and labeled at 85° C.

In the switching section, another two MDF18N50 MOSFETs are used in the traditional two-transistor forward configuration. The specifications for these transistors were already posted above.

Figure 12: Switching transistors

The primary is controlled by the omnipresent CM6800 active PFC/PWM combo controller.

Figure 13: Active PFC/PWM combo controller

Let’s now take a look at the secondary of this power supply.

[nextpage title=”Secondary Analysis”]

The Enermax NAXN 80+ 600 W has seven Schottky rectifiers attached to the secondary heatsink.

The maximum theoretical current each line can deliver is given by the formula I / (1 – D) where D is the duty cycle used and I is the maximum current supported by the rectifying diode. As an exercise, we can assume a duty cycle of 30 percent.

The +12 V output uses four SBR30A60CT Schottky rectifiers (30 A, 15 A per internal diode at 110°, 0.60 V maximum voltage drop), giving us a maximum theoretical current of 86 A or 1,029 W for this output.

The +5 V output uses two SBR30U30CT Schottky rectifiers (30 A, 15 A per internal diode at 140° C, 0.54 V maximum voltage drop), giving us a maximum theoretical current of 43 A or 214 W for this output.

The +3.3 V output uses one STPS4045CW Schottky rectifier (40 A, 20 A per internal diode at 150° C, 0.94 V maximum voltage drop), giving us a maximum theoretical current of 29 A or 94 W for this output.

Figure 14: The +12 V, +5 V, and +3.3 V rectifiers

This power supply uses an ST9S429 monitoring integrated circuit, which apparently is a rebranded S3515. This chip supports over voltage (OVP), under voltage (UDP), and over current (OCP) protections. There are two +12 V OCP channels, matching the number of +12 V rails advertised by the manufacturer.

Figure 15: Monitoring circuit

The electrolytic capacitors available in the secondary are from Teapo and Samxon and labeled at 105° C.

[nextpage title=”Power Distribution”]

In Figure 16, you can see the power supply label containing all the power specs.

Figure 16: Power supply label

This power supply is sold as having two +12 V rails. We could clearly see one “shunt” (current sensor) for each +12 V “rail,” and the monitoring integrated circuit has two +12 V over current protection channels. Click here to understand more about this subject.

The two +12 V rails are distributed like this:

• +12V1 (solid yellow wire): All cables but the ATX12V/EPS12V
• +12V2 (yellow/black wires): The ATX12V/EPS12V cable

This distribution is perfect, as it puts the CPU (ATX12V/EPS12V) and the video card in separate rails.

How much power can this unit really deliver? Let’s find out.

[nextpage title=”Load Tests”]

We conducted several tests with this power supply, as described in the article Hardware Secrets Power Supply Test Methodology.  

First we tested this power supply with five different load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching the behavior of the reviewed unit under each load. In the table below, we list the load patterns we used and the results for each load.

If you add all the powers listed for each test, you may find a different value than what is posted under “Total” below. Since each output can have a slight variation (e.g., the +5 V output working at +5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. In the “Total” row, we are using the real amount of power being delivered, as measured by our load tester.

The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test, the +12VA input was connected to the power supply +12V1 rail, while the +12VB input was connected to the power supply +12V2 rail.

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12VA	4 A (48 W)	9 A (108 W)	13 A (156 W)	17.5 A (210 W)	21.5 A (258 W)
+12VB	4 A (48 W)	9 A (108 W)	13 A (156 W)	17.5 A (210 W)	21 A (252 W)
+5 V	1 A (5 W)	2 A (10 W)	4 A (20 W)	6 A (30 W)	10 A (50 W)
+3.3 V	1 A (3.3 W)	2 A (6.6 W)	4 A (13.2 W)	6 A (19.8 W)	10 A (33 W)
+5VSB	1 A (5 W)	1 A (5 W)	1.5 A (7.5 W)	2 A (10 W)	3 A (15 W)
-12 V	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)
Total	113.6 W	238.6 W	350.6 W	472.5 W	595.8 W
% Max Load	18.9%	39.8%	58.4%	78.8%	99.3%
Room Temp.	46.6° C	45.1° C	45.7° C	47.9° C	49.3° C
PSU Temp.	49.7° C	49.0° C	49.0° C	49.8° C	52.2° C
Voltage Regulation	Pass	Pass	Pass	Pass	Pass
Ripple and Noise	Pass	Pass	Pass	Pass	Pass
AC Power	133.6 W	275.5 W	411.6 W	568.4 W	742.8 W
Efficiency	85.0%	86.6%	85.2%	83.1%	80.2%
AC Voltage	119.1 V	117.9 V	116.3 V	114.5 V	113.5 V
Power Factor	0.956	0.981	0.989	0.993	0.995
Final Result	Pass	Pass	Pass	Pass	Pass

The Enermax NAXN 80+ 600 W can really deliver its labeled wattage at high temperatures.

Efficiency was high when we pulled between 20% and 80% of the labeled wattage (i.e., between 120 W and 480 W), ranging from 83.1% and 86.6%. At 600 W, efficiency dropped to 80.2%, matching the standard 80 Plus certification.

Voltages were always inside the allowed range (±5% for the positive voltages and ±10% for the negative voltages), but above the ±3% tolerance that we like to see to consider a power supply “flawless.” For example, during test one, the +5 V output was at +5.20 V, and during test five, this same output was at +4.80 V, while the +12 V output was at +11.57 V.

Noise and ripple levels were always very low. Below you can see the results for the power supply outputs during test number five. The maximum allowed is 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V, +3.3 V and +5VSB outputs. All values are peak-to-peak figures.

Figure 17: +12VA input from load tester during test five at 595.8 W (51.4 mV)

Figure 18: +12VB input from load tester during test five at 595.8 W (56.8 mV)

Figure 19: +5V rail during test five at 595.8 W (9.6 mV)

Figure 20: +3.3 V rail during test five at 595.8 W (14.4 mV)

Let’s see if we can pull more than 600 W from this unit.

[nextpage title=”Overload Tests”]

Below you can see the maximum we could pull from this power supply. We couldn’t pull more than that because the power supply shut down, showing that its protections were working just fine. However, after a few minutes working with this configuration, the power supply burned. The component that burned was one of the +12 V rectifiers. During this test the noise levels at the +12 V outputs were above the maximum allowed (175.4 mV at +12VA and 375.4 mV at +12VB).

Input	Overload Test
+12VA	26 A (312 W)
+12VB	26 A (312 W)
+5 V	12 A (60 W)
+3.3 V	12 A (39.6 W)
+5VSB	3 A (15 W)
-12 V	0.5 A (6 W)
Total	710.4 W
% Max Load	118.4%
Room Temp.	48.3° C
PSU Temp.	52.3° C
AC Power	938 W
Efficiency	75.7%
AC Voltage	111.7 V

[nextpage title=”Main Specifications”]

The main specifications for the Enermax NAXN 80+ 600 W power supply include:

• Standards: NA
• Nominal labeled power: 600 W
• Measured maximum power: 710.4 W at 48.3° C ambient
• Labeled efficiency: Between 80% and 86%, 80 Plus standard certification
• Measured efficiency: Between 80.2% and 86.6%, at 115 V (nominal, see complete results for actual voltage)
• Active PFC: Yes
• Modular Cabling System: No
• Motherboard Power Connectors: One 20/24-pin connector and two ATX12V connectors that together form an EPS12V connector
• Video Card Power Connectors: Two six/eight-pin connectors on separate cables
• SATA Power Connectors: Seven on two cables
• Peripheral Power Connectors: Four on two cables
• Floppy Disk Drive Power Connectors: One
• Protections (as listed by the manufacturer): Over voltage (OVP), under voltage (UVP), over power (OPP), and short-circuit (SCP) protections
• Are the above protections really available? Yes. Over current protection (OCP) not listed by present.
• Warranty: Three years
• More Information: https://www.enermax.com
• Average Price in the US*: USD 70.00

* Researched at Newegg.com on the day we published this review.

[nextpage title=”Conclusions”]

The Enermax NAXN 80+ 600 W is a power supply targeted to the average user. For this kind of user, it provides a very good value, with high efficiency ranging from 83.1% to 86.6% if you pull between 120 W and 480 W (dropping to 80.2% at 600 W), very low noise and ripple levels, and very good cable configuration (not many 600 W units provide seven SATA power connectors). Voltage regulation, although not “flawless,” is acceptable, especially for the market share this unit is targeted at.

Its price, USD 70, is not bad at all. The reviewed unit has similar efficiency (except for the full load test) as the Cooler Master Silent Pro M 600 W, which costs USD 100. Also, USD 70 is the same price as the Corsair CX600 V2, a power supply that, as far as we can tell, is internally identical to the Enermax NAXN 80+ 600 W. The Enermax model has the advantage of costing only USD 40 after sending a mail-in rebate card. A rebate card is also available for the Corsair model, but the final price after rebate comes to USD 50. It’s a shame that some users forget to fill out and send rebate cards.

Of course, if you are an exigent user, you will probably want a better unit, but you will have to pay more.

As a final comment, we find it strange that Enermax, a company that designs power supplies and has its own manufacturing facilities, decided to buy power supplies
from someone else.