Sentey Golden Steel Power 850 W Power Supply Review
By Gabriel Torres on May 24, 2011


Introduction

Hardware Secrets Golden Award

The Golden Steel Power is an 80 Plus Gold power supply series from Sentey, featuring a modular cabling system, resonant switching, synchronous rectification, and DC-DC design, coming with a terrific price tag for the features offered. Let’s see if the 850 W model is a good option.

The Golden Steel Power units from Sentey are manufactured by Super Flower, based on their Golden Green platform, which is also used by the NZXT HALE90 power supply series. Therefore, the Sentey Golden Steel Power 850 W is identical to the NZXT HALE90 850 W unit, which we’ve already reviewed.

Sentey Golden Steel Power 850 W power supply
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Figure 1: Sentey Golden Steel Power 850 W power supply

Sentey Golden Steel Power 850 W power supply
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Figure 2: Sentey Golden Steel Power 850 W power supply

The Sentey Golden Steel Power 850 W is 7.1” (180 mm) deep, using a 140 mm dual-ball-bearing fan on its bottom.

The reviewed unit has a modular cabling system with eight connectors. One interesting thing about this modular cabling system is that there is no specific connector for the video cards or for the peripheral cables; you can install the cables wherever you want. The unit also has four cables that are permanently attached to its body, all protected by nylon sleeves (coming from inside the power supply housing). The cables included are the following:

We saw some small differences between the Sentey Golden Steel Power 850 W and the NZXT HALE90 850 W. On the Sentey model, the cables are a little shorter. The NZXT model comes with one cable with four SATA power connectors permanently attached to the power supply, while on the Sentey model this cable is available on the modular cabling system. The NXZT model has one additional cable with peripheral power connectors on the modular cabling system.

All wires are 18 AWG, except the ones used on the main motherboard cable and on the ATX12V/EPS12V cables, which are thicker (16 AWG).

The cable configuration is impressive, allowing you to install up to three high-end video cards without using adapters, and the 10 SATA power connectors will please even the über storage-freak user. The only thing we didn’t like was the fact that the video card connectors that are permanently attached to the power supply are installed on the same cable instead of using individual cables.

Sentey Golden Steel Power 850 W power supply
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Figure 3: Cables

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

A Look Inside the Sentey Golden Steel Power 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.

In 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 is identical to the NZXT HALE90 850 W.

Sentey Golden Steel Power 850 W power supply
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Figure 4: Top view

Sentey Golden Steel Power 850 W power supply
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Figure 5: Front quarter view

Sentey Golden Steel Power 850 W power supply
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Figure 6: Rear quarter view

Sentey Golden Steel Power 850 W power supply
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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. 

This power supply has all the required components except for the MOV, which is in charge of removing spikes coming from the power grid. On the other hand, it has two Y capacitors and one X capacitor more than the minimum required.

Sentey Golden Steel Power 850 W power supply
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Figure 8: Transient filtering stage (part 1)

Sentey Golden Steel Power 850 W power supply
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Figure 9: Transient filtering stage (part 2)

Now let’s have a more detailed discussion of the components used in the Sentey Golden Steel Power 850 W.

Primary Analysis

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

This power supply uses one US30KB80R rectifying bridge, attached to the same heatsink used by the active PFC and switching transistors. This bridge supports up to 30 A at 97° C so, in theory, you would be able to pull up to 3,450 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 2,760 W without burning itself out. Of course, we are only talking about these components. The real limit will depend on all the other components of this power supply.

Sentey Golden Steel Power 850 W power supply
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Figure 10: Rectifying bridge

The active PFC circuit uses two IPI60R125CP MOSFETs, each one capable of delivering up to 25 A at 25° C or up to 16 A at 100° C in continuous mode (note the difference temperature makes), or up to 82 A at 25° C in pulse mode. These transistors present a 125 mΩ resistance when turned on, a characteristic called RDS(on). The lower this number, the better, meaning that the transistors will waste less power, and the power supply will have a higher efficiency.

This power supply uses two electrolytic capacitors to filter the output from the active PFC circuit. The Sentey Golden Steel Power 850 W uses two 390 µF x 400 V capacitors connected in parallel, the equivalent of one 780 µF x 400 V capacitor. They are Japanese, manufactured by Chemi-Con, and labeled at 105° C.

Instead of using a PWM/PFC combo controller, this power supply uses two separate circuits, and the active PFC circuit is controlled by an NCP1653A integrated circuit.

Sentey Golden Steel Power 850 W power supply
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Figure 11: Active PFC controller

In the switching section, another two IPI60R125CP MOSFET transistors are used. The specifications for these transistors are already published above.

Sentey Golden Steel Power 850 W power supply
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Figure 12: Active PFC transistors, active PFC diode, and switching transistors

Power supplies from the Sentey Golden Steel Power series use an LLC resonant switching design. The switching transistors are controlled by an SF29601 controller, but we couldn’t find more information about this chip. We believe that the original manufacturer got a resonant controller and relabeled it, as SF stands for “Super Flower.” Interestingly enough, the controller is placed in the secondary of the power supply.

Sentey Golden Steel Power 850 W power supply
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Figure 13: LLC resonant controller

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

Secondary Analysis

This power supply uses a synchronous design in its secondary, meaning that the Schottky rectifiers were replaced by MOSFET transistors in order to increase efficiency. On top of that, this unit uses a DC-DC design, meaning that this unit is basically a +12 V power supply, with the +5 V and +3.3 V outputs being generated by two small power supplies attached to the +12 V output.

The +12 V output is generated by six IPP040N06N3 MOSFETs, each one capable of handling up to 90 A at 100⁰ C in continuous mode, or up to 360 A at 25⁰ C in pulse mode, with an RDS(on) of only 3.7 mΩ. In this power supply, the +12 V output is also used to generate the +5 V and the +3.3 V outputs, as you know. As an exercise, if we assume that all load was exclusively pulled from the +12 V output, we would have a maximum theoretical current limit of 386 A or 4,629 W.

Sentey Golden Steel Power 850 W power supply
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Figure 14: +12 V transistors

Usually, power supplies that use DC-DC converters in the secondary to generate the +5 V and +3.3 V outputs have two separate printed circuit boards, one for each output. The Sentey Golden Steel Power 850 W, however, has a single printed board hosting both circuits.

Each converter is based on one NCP1587A PWM controller and four ME70N03S MOSFETs, each one with a current limit of 62 A at 25° C or 50 A at 70° C in continuous mode, or up to 100 A at 25° C in pulse mode, with a maximum RDS(on) of 11 mΩ.

Sentey Golden Steel Power 850 W power supply
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Figure 15: The DC-DC converter

Sentey Golden Steel Power 850 W power supply
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Figure 16: The DC-DC converter

We didn’t see an integrated circuit for monitoring the power supply outputs, and since the Power Good wire and sensors were connected to the small printed circuit board to where the resonant controller was attached, our best guess is that the enigmatic SF29601 controller, with the aid of four operational amplifiers provided by an LM324 integrated circuit, do the trick.

The electrolytic capacitors available in the secondary are also from Chemi-Con and labeled at 105° C.

Power Distribution

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

Sentey Golden Steel Power 850 W power supply
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Figure 17: Power supply label

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

Let’s now see if this power supply can really deliver 850 W.

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 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)

20 A (240 W)

25 A (300 W)

31 A (372 W)

+12VB

 6 A (72 W)

13 A (156 W)

17 A (204 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)

10 A (50 W)

+3.3 V

2 A (6.6 W)

4 A (13.2 W)

6 A (30 W)

8 A (26.4 W)

10 A (33 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

175.5 W

353.3 W

518.9 W

690.7 W

850.4 W

% Max Load

20.6%

41.6%

61.0%

81.3%

100.0%

Room Temp.

46.6° C

46.1° C

46.8° C

48.2° C

46.4° C

PSU Temp.

46.1° C

47.0° C

47.8° C

49.0° C

51.5° C

Voltage Regulation

Pass

Pass

Pass

Pass

Pass

Ripple and Noise

Pass

Pass

Pass

Pass

Pass

AC Power

198.2 W

392.4 W

578.2 W

784.0 W

984.0 W

Efficiency

88.5%

90.0%

89.7%

88.1%

86.4%

AC Voltage

115.5 V

113.3 V

111.2 V

108.6 V

106.9 V

Power Factor

0.981

0.991

0.994

0.995

0.995

Final Result

Pass

Pass

Pass

Pass

Pass

The Sentey Golden Steel Power 850 W can really deliver its labeled wattage at high temperatures.

Efficiency was very high, always above 86% and peaking at 90% when we pulled around 350 W from the reviewed unit. The efficiency numbers are great, but at full load, efficiency was a little bit below what is required by the 80 Plus Gold certification (87%). This happens because the tests for the 80 Plus certification are conducted at a room temperature of 23° C, while we test power supplies at 45° C minimum, and efficiency drops with temperature.

Voltage regulation was superb, with all voltages within 3% of their nominal values, including the -12 V output. This means that voltages were closer to their nominal values than required by the ATX12V specification, which says positive voltages must be within 5% of their nominal values, and negative voltages must be within 10% of their nominal values.

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.

Sentey Golden Steel Power 850 W power supply
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Figure 18: +12VA input from load tester during test five at 850.4 W (30.6 mV)

Sentey Golden Steel Power 850 W power supply
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Figure 19: +12VB input from load tester during test five at 850.4 W (37.4 mV)

Sentey Golden Steel Power 850 W power supply
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Figure 20: +5V rail during test five at 850.4 W (15 mV)

Sentey Golden Steel Power 850 W power supply
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Figure 21: +3.3 V rail during test five at 850.4 W (22.6 mV)

Let’s see if we can pull even more from the Sentey Golden Steel Power 850 W.

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. We could pull more with the NZXT HALE90 850 W.

Input

Overload Test

+12VA

32.5 A (390 W)

+12VB

33 A (396 W)

+5 V

22 A (110 W)

+3.3 V

22 A (72.6 W)

+5VSB

3 A (15 W)

-12 V

0.5 A (6 W)

Total

988.8 W

% Max Load

116.3%

Room Temp.

44.8° C

PSU Temp.

46.6° C

AC Power

1,181 W

Efficiency

83.7%

AC Voltage

105.3 V

Power Factor

0.995

Main Specifications

The main specifications for the Sentey Golden Steel Power 850 W include:

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

Conclusions

In this review, we discovered that the Sentey Golden Steel Power 850 W is internally identical to, and performed as well as, the NZXT HALE90 850 W power supply. Both are terrific units, with very high efficiency, superb voltage regulation (3% voltage regulation), and very low noise and ripple levels. The Sentey Golden Steel Power 850 W, however, has a big advantage: it is cheaper than the NZXT HALE90 850 W. Costing only USD 160, the Sentey Golden Steel Power 850 W is a no-brainer for users looking for an affordable, high-efficiency 850 W power supply with modular cabling system.

Originally at http://www.hardwaresecrets.com/article/Sentey-Golden-Steel-Power-850-W-Power-Supply-Review/1289


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