High Power Direct12 BR 850 W Power Supply Review
By Gabriel Torres on October 24, 2011


Introduction

High Power is an OEM, i.e., Original Equipment Manufacturer. This means that their core business is manufacturing products for other brands. For instance, some units from OCZ and Enermax, and units from Thortech are manufactured by them. Now, in a move that several other OEMs are also attempting, they want to enter the retail market using their own brand. Let’s see if the Direct12 BR 850 W, a unit with the 80 Plus Bronze certification, modular cabling system, and single +12 V rail, is a good option.

Here is just a little bit of information on the history of this company. Sirtec established Sirfa Electronics in 1996, and in 2008 Sirtec sold Sirfa. Sirfa then created the High Power brand in 2008. In some forums, you will still find some people saying that Sirfa and Sirtec are the same company, although they broke up in 2008.

Internally, this unit seems to be identical to the Enermax NAXN 82+ 850 W. However, since we haven’t reviewed this unit from Enermax, we can’t say this with total certainty.

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 1: High Power Direct12 BR 850 W power supply

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 2: High Power Direct12 BR 850 W power supply

The High Power Direct12 BR 850 W is 6.3” (160 mm) deep, using a 135 mm ball bearing fan on its bottom (Globe Fan RL4Z-B1352512H).

This unit has a modular cabling system with eight connectors, four for video cards (red) and four for SATA and peripheral power connectors (black). The motherboard cables are permanently attached to the power supply, and they are protected with nylon sleeves that come from inside the unit. This power supply comes with the following cables:

All wires are 18 AWG, which is the minimum recommended gauge, except for the main motherboard cable, which uses thicker 16 AWG wires.

The cable configuration is outstanding, with a total of eight power connectors for video cards, allowing you to install four high-end video cards at the same time without the need for adapters, and 12 SATA power connectors.

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 3: Cables

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

A Look Inside the High Power Direct12 BR 850 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 mentioned, this unit seems to be identical to the Enermax NAXN 82+ 850 W.

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 4: Top view

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 5: Front quarter view

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 6: Rear quarter view

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 7: The printed circuit board

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 stage, this power supply is flawless, with one X capacitor, two Y capacitors, and one ferrite coil more than the minimum required.

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 8: Transient filtering stage (part 1)

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 9: Transient filtering stage (part 2)

On the next page, we will have a more detailed discussion about the components used in the High Power Direct12 BR 850 W.

Primary Analysis

On this page we will take an in-depth look at the primary stage of the High Power Direct12 BR 850 W. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.

This power supply uses one GBJ2506 rectifying bridge, which is attached to the same heatsink as the active PFC components. This bridge supports up to 25 A at 100° C, so in theory, you would be able to pull up to 2,875 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 2,300 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.

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 10: Rectifying bridge

The active PFC circuit uses two SPW24N60C3 MOSFETs, each supporting up to 24.3 A at 25° C or 15.4 A at 100° C in continuous mode (note the difference temperature makes), or 72.9 A at 25° C in pulse mode. These transistors present a 160 mΩ resistance when turned on, a characteristic called RDS(on). The lower the number the better, meaning that the transistor will waste less power, and the power supply will have a higher efficiency.

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 11: The active PFC transistors

The output of the active PFC circuit is filtered by a Japanese capacitor, from Chemi-Con, labeled at 105° C.

In the switching section, another two SPW24N60C3 MOSFETs are used in the traditional two-transistor forward configuration. The specifications for these transistors were discussed above.

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 12: The switching transistors

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

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 13: Active PFC/PWM combo controller

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

Secondary Analysis

The High Power Direct12 BR 850 W uses a regular design in its secondary, with Schottky rectifiers.

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 KCQ60A06 Schottky rectifiers (60 A, 30 A per internal diode at 69° C, 0.67 V maximum voltage drop). This gives us a maximum theoretical current of 171 A or 2,057 W for the +12 V output.

The +5 V output uses two PFR30L45CT Schottky rectifiers (30 A, 15 A per internal diode at 110° C, 0.52 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 another two PFR30L45CT Schottky rectifiers (30 A, 15 A per internal diode at 110° C, 0.52 V maximum voltage drop), giving us a maximum theoretical current of 43 A or 141 W for this output.

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 14: The +5 V, +3.3 V, and +12 V rectifiers

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 15: The +12 V, +3.3 V, +5 V, and +5VSB rectifiers

This power supply uses a PS224 monitoring integrated circuit, which supports over voltage (OVP), under voltage (UVP), and over current (OCP) protections. This chip offers two +12 V channels. However, the manufacturer decided to use only one of them and provide a single +12 V rail.

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 16: Monitoring circuit

The electrolytic capacitors that filter the outputs are from Teapo and labeled at 105° C, as usual. On the modular cabling system printed circuit board, however, the manufacturer added Japanese capacitors, also from Chemi-Con, and some solid models. They seem to be jerry-rigged to this printed circuit board, though.

Power Distribution

In Figure 17, you can see the power supply label containing all the power specs.

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 17: Power supply label

This power supply has a single +12 V rail, so there is not much to talk about here.

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

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, both inputs were connected to the power supply’s single +12 V rail.

Input

Test 1

Test 2

Test 3

Test 4

Test 5

+12VA

6 A (72 W)

13 A (156 W)

18.5 A (222 W)

25 A (300 W)

31 A (372 W)

+12VB

6 A (72 W)

13 A (156 W)

18.5 A (222 W)

25 A (300 W)

31 A (372 W)

+5 V

2 A (10 W)

4 A (20 W)

6 A (30 W)

8 A (40 W)

12 A (60 W)

+3.3 V

2 A (6.6 W)

4 A (13.2 W)

6 A (19.8 W)

8 A (26.4 W)

12 A (39.6 W)

+5VSB

1 A (5 W)

1.5 A (7.5 W)

2 A (10 W)

2.5 A (12.5 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

174.6 W

362.8 W

512.9 W

684.9 W

847.1 W

% Max Load

20.5%

42.7%

60.3%

80.6%

99.7%

Room Temp.

44.8° C

44.8° C

45.0° C

49.6° C

45.6° C

PSU Temp.

49.1° C

49.1° C

50.6° C

52.3° C

56.3° C

Voltage Regulation

Pass

Pass

Pass

Pass

Failed at +3.3 V

Ripple and Noise

Pass

Pass

Pass

Pass

Pass

AC Power

208.4 W

422.1 W

601.2 W

813.0 W

1031.0 W

Efficiency

83.8%

86.0%

85.3%

84.2%

82.2%

AC Voltage

117.2 V

114.5 V

112.8 V

110.8 V

106.8 V

Power Factor

0.926

0.974

0.984

0.988

0.992

Final Result

Pass

Pass

Pass

Pass

Fail

The High Power Direct12 BR 850 W can really deliver its labeled wattage at high temperatures.

Efficiency was between 82.2% and 86.0% during our tests. It is great to see that this unit can really present efficiency above 82% at full load under higher temperatures, since several power supplies with the 80 Plus Bronze certification fail to provide 82% minimum efficiency under this scenario. Voltages were closer to their nominal values (3% regulation) during tests one, two, and three, which is great. During test four, the +3.3 V output was outside this tighter range (at +3.17 V), but still inside the allowed margin. During test five, however, the +3.3 V output was below the minimum allowed, at +3.10 V. The ATX12V specification states that positive voltages must be within 5% of their nominal values, and negative voltages must be within 10% of their nominal values.

Let’s discuss the ripple and noise levels on the next page.

Ripple and Noise Tests

Voltages at the power supply outputs must be as “clean” as possible, with no noise or oscillation (also known as “ripple”). The maximum ripple and noise levels allowed are 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. We consider a power supply as being top-notch if it can produce half or less of the maximum allowed ripple and noise levels.

The High Power Direct12 BR 850 W provided very low ripple and noise levels, as you can see in the table below.

Input

Test 1

Test 2

Test 3

Test 4

Test 5

+12VA

9.6 mV

12.8 mV

13.8 mV

17.6 mV

20.2 mV

+12VB

10.8 mV

14.4 mV

18.2 mV

24.8 mV

29.6 mV

+5 V

9.4 mV

10.4 mV

7.2 mV

6.6 mV

8.6 mV

+3.3 V

9.6 mV

10.4 mV

10.8 mV

11.6 mV

14.0 mV

+5VSB

6.6 mV

13.4 mV

11.4 mV

15.4 mV

11.4 mV

-12 V

46.2 mV

44.4 mV

45.2 mV

47.2 mV

54.2 mV

Below you can see the waveforms of the outputs during test five.

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 18: +12VA input from load tester during test five at 847.1 W (20.2 mV)

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 19: +12VB input from load tester during test five at 847.1 W (29.6 mV)

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 20: +5V rail during test five at 847.1 W (29.6 mV)

High Power Direct12 BR 850 W power supply
click to enlarge
Figure 21: +3.3 V rail during test five at 847.1 W (14 mV)

Let’s see if we can pull more than 850 W from this unit.

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 well. During this test, all voltages were still inside the tighter 3% regulation, except the +3.3 V output, which was way below the minimum allowed, at +3.02 V. Ripple and noise levels were still very low, except at the -12 V output, at 104.5 mV (still below the maximum allowed).

Input

Overload Test

+12VA

33 A (396 W)

+12VB

33 A (396 W)

+5 V

23 A (115 W)

+3.3 V

23 A (75.9 W)

+5VSB

3 A (15 W)

-12 V

0.5 A (6 W)

Total

987.3 W

% Max Load

116.2%

Room Temp.

49.1° C

PSU Temp.

59.6° C

AC Power

1,266 W

Efficiency

78.0%

AC Voltage

103.9 V

Power Factor

0.993

Main Specifications

The main specifications for the High Power Direct12 BR 850 W power supply include:

Conclusions

The High Power Direct12 BR 850 W power supply seems to be internally identical to the Enermax NAXN 82+ 850 W. It can really deliver its labeled wattage at high temperatures, and it presented efficiency between 82.2% and 86% during our tests and very low noise and ripple levels. One of the highlights of this product is the cable configuration, with eight video card power connectors, allowing you to hook up to four high-end video cards, and 12 SATA power connectors.

This unit, however, has some issues. First, when we turned it on for the first time, it started making an annoying ticking sound. Upon checking it out, we discovered that one of the cable ties inside the unit was touching the fan. This was an easy fix, but we wonder if the average user will dare to stick a screwdriver through the fan mesh to push the cable that was causing the problem.

The second minor problem, which unfortunately seems to plague all Chinese manufacturers, is the website written in “Engrish.” How much would it cost to hire a proofreader and avoid fantastic sentences such as “Its tailor-made single +12V rail is the arsenal for you to become Guru of Overclocker!” (Note to High Power: the correct structure would be “Its tailor-made single +12V rail is the arsenal for you to become the overclocking guru!”)

All these problems are minor. The only real problem we found with this unit was with its +3.3 V output, which drops below the minimum allowed at full load.

The manufacturer suggested price is USD 160, and we know that online stores rarely sell power supplies at their suggested price; they always give discounts. Therefore, if it is sold for, say, USD 150, it will compete directly with the Corsair TX850M.

Originally at http://www.hardwaresecrets.com/article/High-Power-Direct12-BR-850-W-Power-Supply-Review/1411


© 2004-13, Hardware Secrets, LLC. All Rights Reserved.

Total or partial reproduction of the contents of this site, as well as that of the texts available for downloading, be this in the electronic media, in print, or any other form of distribution, is expressly forbidden. Those who do not comply with these copyright laws will be indicted and punished according to the International Copyrights Law.

We do not take responsibility for material damage of any kind caused by the use of information contained in Hardware Secrets.