FSP Aurum Gold 700 Power Supply Review
By Gabriel Torres on March 23, 2011


Introduction

Hardware Secrets Golden Award

FSP is a traditional OEM manufacturer that is also offering some retail products. One of their latest offerings is the Aurum Gold series, with 400 W, 500 W, 600 W, and 700 W models featuring 80 Plus Gold certification. Let’s see if the 700 W model is a good buy.

Like most OEM manufacturers, FSP is plagued with an identity crisis: they have four different websites, http://www.fsp-group.com.tw, http://www.fspgroupusa.com, http://www.fsplifestyle.com and http://www.fspgroup.com, which only causes confusion. Not to mention the brand Sparkle (SPI), that belongs to FSP and has a separate website at http://www.sparklepower.com and no one at FSP could explain us exactly why they maintain this separate brand. Like what happens with other manufacturers trying to move from being an OEM manufacturer to a retail brand, they try (without success) separate each branch of business in a different website, but this only causes confusion with consumers. After all, the company is only one. It would be easier for everybody if they only had one website.

FSP Aurum Gold 700 power supply
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Figure 1: FSP Aurum Gold 700 power supply

FSP Aurum Gold 700 power supply
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Figure 2: FSP Aurum Gold 700 power supply

The Aurum Gold 700 is only 5.5” (140 mm) deep, with a 120 mm fluid dynamic bearing fan (Protechnic Electric MGA12012HF-A25, 2,400 rpm, 84.8 cfm, 37 dBA) on its bottom part.

The new FSP Aurum Gold 700 doesn’t have a modular cabling system. All cables are protected with nylon sleeves. The power supply comes with the following cables:

All wires are 18 AWG, which is the minimum recommended gauge.

The number of connectors available is adequate for a 700 W unit, but we found it strange the use of a cable with two ATX12V connectors and an EPS12V connector, since the two ATX12V connectors already provide an EPS12V connector when placed together, and with motherboards that have two EPS12V connectors it is better to have the EPS12V connectors on separate cables. We also prefer to see the video card power connectors on separate cables.

FSP Aurum Gold 700 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 FSP Aurum Gold 700

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.

FSP Aurum Gold 700 power supply
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Figure 4: Top view

FSP Aurum Gold 700 power supply
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Figure 5: Front quarter view

FSP Aurum Gold 700 power supply
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Figure 6: Rear quarter view

FSP Aurum Gold 700 power supply
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Figure 7: 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. 

The transient filtering stage of the FSP Aurum Gold 700 has two Y capacitors and one ferrite coil more than the minimum required, however it doesn’t come with an MOV, component in charge of removing spikes coming from the power grid.

FSP Aurum Gold 700 power supply
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Figure 8: Transient filtering stage (part 1)

FSP Aurum Gold 700 power supply
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Figure 9: Transient filtering stage (part 2)

In the next page we will have a more detailed discussion about the components used in the FSP Aurum Gold 700.

Primary Analysis

On this page we will take an in-depth look at the primary stage of the FSP Aurum Gold 700. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one GBU1506 rectifying bridge, which is attached to an individual heatsink. This bridge supports up to 15 A at 55° 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 component, and the real limit will depend on all the other components in this power supply.

FSP Aurum Gold 700 power supply
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Figure 10: Rectifying bridge

The active PFC circuit uses two IPB60R165CP MOSFETs, which are capable of delivering up to 21 A at 25° C or up to 13 A at 100° C (note the difference temperature makes) in continuous mode, or up to 61 A in pulse mode at 25° C, each. These transistors present a 165 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 achieve a higher efficiency.

The capacitor used to filter the output of the active PFC circuit is Japanese, from Rubycon, and labeled at 105° C.

In the switching section, FSP decided to use a very unique design, called active clamp reset forward, and it seems that FSP put a lot of effort in developing this design. The switching transistor is an SPA17N80C3 MOSFET, which is capable of delivering up to 17 A at 25° C or up to 11 A at 100° C (note the difference temperature makes) in continuous mode, or up to 51 A in pulse mode at 25° C. This transistor presents a 290 mΩ RDS(on). A second transistor (resetting transistor) is used to turn off the switching transistor and is controlled from the secondary side.

FSP Aurum Gold 700 power supply
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Figure 11: Switching transistor, resetting transistor, active PFC diode and active PFC transistors

The primary is controlled by an FSP6600 PFC/PWM combo controller, which is either developed by FSP or a rebranded integrated circuit. In either case, we couldn’t find more information about it.

FSP Aurum Gold 700 power supply
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Figure 12: Active PFC/PWM combo controller

Now let's take a look at the secondary of this power supply.

Secondary Analysis

This power supply uses a synchonous design in its secondary, meaning that the diodes were replaced with transistors in order to increase efficiency.

The +12 V output is rectified using two IRLB3036 MOSFETs, each one capable of handling up to 270 A at 25° C or up to 190 A at 100° C in continuous mode, or up to 1,100 A at 25° C in pulse mode. This translates into a maximum theoretical current of 271 A at 100° C or 3,257 W!

FSP Aurum Gold 700 power supply
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Figure 13: +12 V transistors

The +5 V and +3.3 V outputs share the same circuitry and are rectified by two IPD031N03L MOSFETs – 90 A at 100° C in continuous mode and 400 A at 25° C in pulse mode, 3.1 mΩ RDS(on) – and two IPD050N03L MOSFETs. The four transistors are located on the solder side of the printed circuit board.

FSP Aurum Gold 700 power supply
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Figure 14: The +5 V and +3.3 V transistors

The secondary transistors are controlled by an FSP6601, another proprietary chip from FSP.

FSP Aurum Gold 700 power supply
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Figure 15: Synchronous controller

The secondary is monitored by a WT7579 integrated circuit, which is manufactured exclusively for FSP. This chip supports over voltage (OVP), under voltage (UVP), overcurrent (OCP), and over temperature (OTP) protections. There are four +12 V over current protection (OCP) channels, matching the number of +12 V rails advertised by the manufacturer.

FSP Aurum Gold 700 power supply
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Figure 16: Monitoring circuit

All electrolytic capacitors used in the secondary are from CapXon and labeled at 105° C.

Power Distribution

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

FSP Aurum Gold 700 power supply
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Figure 17: Power supply label

As you can see, the manufacturer lists this unit as having four +12 V rails. Analyzing the circuit, we could clearly see four “shunts” (current sensors), matching the number of rails advertised by the manufacturer, see Figure 18.

FSP Aurum Gold 700 power supply
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Figure 18: Shunts

The available +12 V rails are distributed like this:

This distribution is perfect, as it separates the CPU and the video card power cables on individual rails. However, if you have only one video card with two power connectors, we recommend you to use one connector from each available cable instead of using the two power connectors available on one of the cables.

Let’s now see if this power supply can really deliver 700 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 our tests, the +12VA input was connected to the power supply +12V1 and +12V3 rails, and the +12VB input was connected to the power supply +12V2 rail.

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)

+5V

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 (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

137.5 W

277.1 W

414.5 W

538.7 W

695.1 W

% Max Load

19.6%

39.6%

59.2%

77.0%

99.3%

Room Temp.

44.8° C

43.9° C

44.9° C

47.1° C

47.5° C

PSU Temp.

42.4° C

42.9° C

43.4° C

44.3° C

46.5° C

Voltage Regulation

Pass

Pass

Pass

Pass

Pass

Ripple and Noise

Pass

Pass

Pass

Pass

Pass

AC Power

153.1 W

304.2 W

459.9 W

606.1 W

801.0 W

Efficiency

89.8%

91.1%

90.1%

88.9%

86.8%

AC Voltage

117.6 V

116.1 V

114.7 V

113.2 V

111.3 V

Power Factor

0.985

0.996

0.998

0.999

0.999

Final Result

Pass

Pass

Pass

Pass

Pass

The FSP Aurum Gold 700 can really deliver its labeled wattage at high temperatures.

Efficiency was extremely high when we pulled between 20% and 80% of the power supply labeled wattage (i.e., between 140 W and 560 W), between 89% and 91%, dropping to 86.8% at full load.

Voltage regulation was very good, with all voltages within 3% of their nominal values, except the -12 V output and the +3.3 V output during tests one and five. The ATX12V specification allows voltages to be up to 5% from their nominal values (10% for the -12 V output). Therefore this power supply presents voltages closer to their nominal values than necessary most of the time.

Noise and ripple levels were below the maximum allowed, but a little bit high for us to consider this a “flawless” unit. Below you can see the results for the power supply outputs during test number five. The maximum allowed is 120 mV for the +12 V and -12 V outputs, and 50 mV for the +5 V, +3.3 V, and +5VSB outputs. All values are peak-to-peak figures.

FSP Aurum Gold 700 power supply
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Figure 19: +12VA input from load tester during test five at 695.1 W (69.2 mV)

FSP Aurum Gold 700 power supply
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Figure 20: +12VB input from load tester during test five at 695.1 W (75.6 mV)

FSP Aurum Gold 700 power supply
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Figure 21: +5V rail during test five at 695.1 W (30.6 mV)

FSP Aurum Gold 700 power supply
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Figure 22: +3.3 V rail during test five at 695.1 W (32.4 mV)

Let’s see if we can pull even more from the FSP Aurum Gold 700.

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. Under this extreme scenario efficiency dropped below 80%.

Input

Overload Test

+12VA

33 A (396 W)

+12VB

33 A (396 W)

+5V

15 A (75 W)

+3.3 V

15 A (49.5 W)

+5VSB

3 A (15 W)

-12 V

0.5 A (6 W)

Total

937.5 W

% Max Load

133.93%

Room Temp.

40.4° C

PSU Temp.

43.6° C

AC Power

1,234 W

Efficiency

77.9%

AC Voltage

110.2 V

Power Factor

0.999

Main Specifications

The specs of the FSP Aurum Gold 700 include:

Conclusions

The FSP Aurum Gold 700 is the perfect solution for users that wanted an 80 Plus Gold power supply but never bought one because of the price. At only USD 130, this unit provides a terrific cost/benefit ratio. The highlight of the product is, of course, efficiency: it was between 89% and 91% when we pulled between 20% and 80% of the power supply labeled wattage (i.e., between 140 W and 560 W), dropping to 86.8% at full load.

Although the perfectionist user may complain about little things here and there (absence of an MOV, cable configuration, voltage regulation could be a little bit better, noise and ripple could be a lot better, efficiency at full load could be a tiny bit better), we think this unit is perfect for the mainstream user who wants to go to the next level in terms of efficiency.

Originally at http://www.hardwaresecrets.com/article/FSP-Aurum-Gold-700-Power-Supply-Review/1228


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