Xigmatek Tauro 700 W Power Supply Review
By Gabriel Torres on July 17, 2012


Introduction

Hardware Secrets Silver Award

The Xigmatek Tauro power supply series is comprised of 400 W, 500 W, 600 W, and 700 W models, with the 80 Plus Bronze certification. Today we are testing the 700 W model to see if it is a good product. Check it out.

The Xigmatek Tauro 700 W is manufactured by Andyson. It is internally identical to the Xilence Redwing Series 700 W R3 and the LC-Power LC8750II V2.3 Prophecy 2

Xigmatek Tauro 700w
click to enlarge
Figure 1: Xigmatek Tauro 700 W power supply

Xigmatek Tauro 700w
click to enlarge
Figure 2: Xigmatek Tauro 700 W power supply

The Xigmatek Tauro 700 W is 6.2” (158 mm) deep, using a 135 mm sleeve-bearing fan on its bottom (Xigmatek DFS132512H, which is actually manufactured by Young Lin Tech).

The reviewed power supply doesn’t have a modular cabling system. All cables are protected with nylon sleeves, but only the sleeve used on the main motherboard cable comes from inside the unit. This power supply comes with the following cables:

The main motherboard cable and the EPS12V/ATX12V cable use thicker 16 AWG wires, while the other wires have the minimum recommended gauge (18 AWG). The number of connectors is perfect.

Xigmatek Tauro 700w
click to enlarge
Figure 3: Cables

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

A Look Inside the Xigmatek Tauro 700 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.

Xigmatek Tauro 700w
click to enlarge
Figure 4: Top view

Xigmatek Tauro 700w
click to enlarge
Figure 5: Front quarter view

Xigmatek Tauro 700w
click to enlarge
Figure 6: Rear quarter view

Xigmatek Tauro 700w
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 the transient filtering stage, this power supply is flawless, with one X capacitor more than the minimum required.

Xigmatek Tauro 700w
click to enlarge
Figure 8: Transient filtering stage (part 1)

Xigmatek Tauro 700w
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 Xigmatek Tauro 700 W.

Primary Analysis

On this page we will take an in-depth look at the primary stage of the Xigmatek Tauro 700 W. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.

This power supply uses one BU1506 rectifying bridge, which is attached to an individual heatsink. This bridge supports up to 15 A at 80° C. So, in theory, you would be able to pull up to 1,725 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 1,380 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.

Xigmatek Tauro 700w
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 (see the difference temperature makes) or 72.9 A at 25° C in pulse mode. These transistors present a maximum 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.

The output of the active PFC circuit is filtered by one 390 µF x 420 V electrolytic capacitor from Teapo, labeled at 85° C.

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

Xigmatek Tauro 700w
click to enlarge
Figure 11: The switching and active PFC transistors

The primary is managed by the famous CM6806 active PFC/PWM combo controller. 

Xigmatek Tauro 700w
click to enlarge
Figure 12: Active PFC/PWM combo controller

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

Secondary Analysis

The Xigmatek Tauro 700 W uses a DC-DC design in its secondary. This means that the power supply is basically a +12 V unit, with the +5 V and +3.3 V outputs produced by two smaller power supplies connected to the main +12 V rail. Also, the +12 V output uses a synchronous design, where the rectifiers were replaced with MOSFETs. Both designs are used to increase efficiency.

The +12 V output uses three IRFB3206GPBF MOSFETs, each supporting up to 120 A at 25° C in continuous mode or 840 A at 25° C in pulse mode, with a maximum RDS(on) of 3 mΩ.

Xigmatek Tauro 700w
click to enlarge
Figure 13: The +12 V MOSFETs

The DC-DC converters are located on two individual daughterboards. Each converter is managed by an APW7073 PWM controller, using four QM3004D MOSFETs, each supporting up to 55 A at 25° C or 45 A at 100° C in continuous mode or 110 A at 25° C in pulse mode, with a maximum RDS(on) of 14 mΩ.

Xigmatek Tauro 700w
click to enlarge
Figure 14: One of the DC-DC converters

Xigmatek Tauro 700w
click to enlarge
Figure 15: One of the DC-DC converters

This power supply uses a PS223 monitoring integrated circuit, which supports over voltage (OVP), under voltage (UVP), and over current (OCP) protections. Even though this chip provides two +12 V over current channels, the manufacturer decided to configure this unit as a single-channel model.

Xigmatek Tauro 700w
click to enlarge
Figure 16: Monitoring circuit

The electrolytic capacitors that filter the outputs are from Teapo and JunFu and labeled at 105° C, as usual.

Power Distribution

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

Xigmatek Tauro 700w
click to enlarge
Figure 17: Power supply label

As you can see, this unit 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. (The power supply’s EPS12V connector was installed on the +12VB input of the load tester.)

Input

Test 1

Test 2

Test 3

Test 4

Test 5

+12VA

4.5 A (54 W)

9.5 A (114 W)

14.5 A (174 W)

19 A (228 W)

25 A (300 W)

+12VB

4.5 A (54 W)

9.5 A (114 W)

14.5 A (174 W)

19 A (228 W)

25 A (300 W)

+5 V

1 A (5 W)

4 A (20 W)

6 A (30 W)

8 A (40 W)

10 A (50 W)

+3.3 V

1 A (3.3 W)

4 A (13.2 W)

6 A (19.8 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

137.8 W

278.2 W

417.7 W

543.4 W

703.4 W

% Max Load

19.7%

39.7%

59.7%

77.6%

100.5%

Room Temp.

45.0° C

45.2° C

46.3° C

47.5° C

45.4° C

PSU Temp.

45.2° C

45.8° C

47.3° C

48.5° C

49.2° C

Voltage Regulation

Pass

Pass

Pass

Pass

Pass

Ripple and Noise

Pass

Pass

Pass

Pass

Pass

AC Power

170.8 W

327.2 W

489.3 W

645.0 W

857.0 W

Efficiency

80.7%

85.0%

85.4%

84.2%

82.1%

AC Voltage

114.4 V

113.1 V

109.1 V

108.4 V

106.2 V

Power Factor

0.977

0.987

0.992

0.993

0.994

Final Result

Pass

Pass

Pass

Pass

Pass

The 80 Plus Bronze certification guarantees minimum efficiencies of 82% at 20% and full loads, and 85% at 50% load. In our tests, the Xigmatek Tauro 700 W presented 80.7% efficiency at 20% load. Unfortunately, we see this happening time and time again, as the 80 Plus tests are conducted at 23° C and we test power supplies between 45° C and 50° C, and efficiency drops with temperature.

All voltages were closer to their nominal values during all tests (3% voltage regulation), except the +5VSB output during test five, which was at +4.82 V, still inside the allowed range. 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 Xigmatek Tauro 700 W provided low ripple and noise levels, as you can see below.

Input

Test 1

Test 2

Test 3

Test 4

Test 5

+12VA

13.4 mV

15.0 mV

19.4 mV

24.6 mV

33.4 mV

+12VB

13.2 mV

14.6 mV

18.0 mV

23.0 mV

31.8 mV

+5 V

10.6 mV

13.0 mV

14.6 mV

16.6 mV

22.8 mV

+3.3 V

13.2 mV

15.4 mV

17.0 mV

21.0 mV

27.2 mV

+5VSB

15.2 mV

18.2 mV

25.6 mV

33.4 mV

45.4 mV

-12 V

7.0 mV

9.4 mV

11.2 mV

14.6 mV

18.4 mV

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

Xigmatek Tauro 700w
click to enlarge
Figure 18: +12VA input from load tester during test five at 703.4 W (33.4 mV)

Xigmatek Tauro 700w
click to enlarge
Figure 19: +12VB input from load tester during test five at 703.4 W (31.8 mV)

Xigmatek Tauro 700w
click to enlarge
Figure 20: +5V rail during test five at 703.4 W (22.8 mV)

Xigmatek Tauro 700w
click to enlarge
Figure 21: +3.3 V rail during test five at 703.4 W (27.2 mV)

Overload Tests

Below you can see the maximum we could pull from this power supply. The objective of this test is to see if the power supply has its protection circuits working properly. This unit passed this test, at it shut down when we tried to pull more than listed in the table below. Noise and ripple levels were still low, and voltages were still within 3% of their nominal values.

Input

Overload Test

+12VA

30 A (360 W)

+12VB

30 A (360 W)

+5 V

10 A (50 W)

+3.3 V

10 A (33 W)

+5VSB

3 A (15 W)

-12 V

0.5 A (6 W)

Total

814.4 W

% Max Load

116.3%

Room Temp.

49.4° C

PSU Temp.

49.2° C

AC Power

1,014 W

Efficiency

80.3%

AC Voltage

105.8 V

Power Factor

0.993

Main Specifications

The main specifications for the Xigmatek Tauro 700 W power supply include:

Conclusions

The Xigmatek Tauro 700 W is a good product for its target audience, with efficiency up to 85%, very good voltage regulation, and low ripple and noise levels. The cable configuration is great for a 700 W product. Efficiency at light load (i.e., 20% load), however, could be better. This unit faces tough competition. The Thermaltake TR2 700 W, which also has the 80 Plus Bronze certification and got great results in our tests, costs USD 90. The In Win GreenMe 750 W has a suggested price of USD 100. We know that USD 99 is the manufacturer suggested retail price, and resellers usually sell for less than the MSRP. The Tauro 700 W is a good pick if it is offered for USD 90 or less. Otherwise, there are better options on the market.

Originally at http://www.hardwaresecrets.com/article/Xigmatek-Tauro-700-W-Power-Supply-Review/1594


© 2004-14, 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.