Thermaltake Toughpower Grand 750 W Power Supply Review

[nextpage title=”Introduction”]

The new Toughpower Grand power supply series from Thermaltake has 80 Plus Gold certification, modular cabling system, and single +12 V rail. So far only two models have been released, 650 W and 750 W. Let’s see if the 750 W model is a good buy.

Power supplies from the Toughpower Grand series are manufactured by CWT.

Figure 1: Thermaltake Toughpower Grand 750 W power supply

Figure 2: Thermaltake Toughpower Grand 750 W power supply

The Thermaltake Toughpower Grand 750 W is 7.1” (180 mm) deep and comes with a 140 mm fan on its bottom (Thermaltake TT-1425, although the real manufacturer and model are Yen Sun Technology Corp. YD121425HB – the unexpected joke was that, instead of writing “Corp.,” the original manufacturer wrote “Copy,” making the company name to read as “Yen Sun Technology Copy”).

The Toughpower Grand 750 W comes with a Thermaltake logo on its rear that glows red when the power supply is on.

The reviewed product has a modular cabling system with eight connectors, four red for video card cables and four black for SATA and peripheral cables. Three cables are permanently attached to the power supply. The unit comes with the following cables:

• Main motherboard cable with a 20/24-pin connector, 21.3” (54 cm) long, permanently attached to the power supply
• One cable with two ATX12V connectors each that together form an EPS12V connector, 21.7” (55 cm) long, permanently attached to the power supply
• One ATX12V extension, 5.9” (15 cm) long
• One cable with one EPS12V connector, 21.7” (55 cm) long, permanently attached to the power supply
• Two cables with one six-pin connector for video cards each, 19.7” (50 cm) long, modular cabling system
• Two cables with one eight-pin connector for video cards each, 19.7” (50 cm) long, modular cabling system
• Two adapters to convert one eight-pin connector for video cards into one six-pin connector, 5.9” (15 cm long)
• Two cables with four SATA power connectors each, 19.7” (50 cm) to the first connector, 5.9” (15 cm) between connectors, modular cabling system
• One cable with four standard peripheral power connectors, 19.7” (50 cm) to the first connector, 5.9” (15 cm) between connectors, modular cabling system
• One cable with four standard peripheral power connectors and one floppy disk drive power connector, 19.7” (50 cm) to the first connector, 5.9” (15 cm) between connectors, modular cabling system

All wires are 18 AWG, which is the minimum recommended gauge, except the wires on the main motherboard cable, which are thicker (16 AWG).

The cable configuration is very good for a 750 W product, allowing you to have up to two high-end video cards without the need of adapters.

Figure 3: Cables

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

[nextpage title=”A Look Inside The Thermaltake Toughpower Grand 750 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.

This page will be an overview, and then in the following pages we will discuss in detail the quality and ratings of the components used.

Figure 4: Top view

Figure 5: Rear quarter view

Figure 6: Front quarter view

Figure 7: 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.   

This power supply has all the minimum required components plus one additional ferrite coil, four additional Y capacitors, one additional X capacitor, and one X capacitor after the rectifying bridge. The MOV is located behind the fuse and can’t be seen in Figure 9.

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 Thermaltake Toughpower Grand 750 W.

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the primary stage of the Thermaltake Toughpower Grand 750 W. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses two GBU806 rectifying bridges, which are attached to the same heatsink where the active PFC transistors are located. Each bridge supports up to 8 A at 100° C so, in theory, you would be able to pull up to 1,840 W from a 115 V power grid. Assuming 80% efficiency, the bridges would allow this unit to deliver up to 1,472 W without burning themselves out. Of course, we are only talking about these components, and the real limit will depend on all the other components in this power supply.

Figure 10: Rectifying bridges

The active PFC circuit uses two SPW35N60C3 MOSFETs, each one capable of delivering up to 34.6 A at 25° C or up to 21.9 A at 100° C (note the difference temperature makes) in continuous mode, or up to 103.8 A in pulse mode at 25° C. These transistors present a 100 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.

Figure 11: 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 SPW35N60C3 MOSFETs are used, installed in the two-transistor forward configuration, and their technical specs were already published above.

Figure 12: Switching transistors

The primary is controlled by the famous CM6800 active PFC/PWM combo controller. This was definitely an unusual choice, since most manufacturers decided to use a resonant project in their 80 Plus Gold power supplies instead of the traditional two-transistor forward configuration.

Figure 13: Active PFC/PWM combo controller

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

[nextpage title=”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 five IPP034NE7N3 MOSFETs, each one capable of handling up to 100 A at 100° C in continuous mode or up to 400 A at 25° C in pulse mode, with an RDS(on) of only 3.4 mΩ. Three of them are used for the direct rectification, while the other two are used for the “freewheeling” part of the rectification.

Figure 14: +12 V transistors

Like most of the power supplies that use DC-DC converters in the secondary to generate the +5 V and +3.3 V outputs, the Toughpower Grand 750 W has two separate printed circuit boards installed in the secondary, one for each output. Each converter is managed by an APW7073 PWM controller and uses two ME90N03 MOSFETs – 60 A at 25° C or 47 A at 70° C in continuous mode, 240 A at 25° C in pulse mode, 9 mΩ RDS(on) –, and two ME70N03S MOSFETs – 62 A at 25° C or 50 A at 70° C in continuous mode, 100 A at 25° C in pulse mode, 11 mΩ RDS(on).

Figure 15: One of the DC-DC converters

Figure 16: One of the DC-DC converters

The secondary is monitored by a PS223 integrated circuit. This chip supports OCP (over current protection), over voltage protection (OVP), under voltage protection (UVP) and over temperature protection (OTP). The over current protection circuit has four channels (+3.3 V, +5 V and two +12 V), but the manufacturer decided to use only one of the available +12 V channels to make this unit to have a single +12 V rail.

Figure 17: Monitoring circuit

Half of the electrolytic capacitors of the secondary are Japanese, from Chemi-Con, and the other half uses solid capacitors.

[nextpage title=”Power Distribution”]

In Figure 18, you can see the power supply label containing all the power specs.

Figure 18: 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 750 W.

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

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12VA	5 A (60 W)	11 A (132 W)	16 A (192 W)	22 A (264 W)	27 A (324 W)
+12VB	5 A (60 W)	10 A (120 W)	16 A (192 W)	21 A (252 W)	27 A (324 W)
+5V	2 A (10 W)	4 A (20 W)	6 A (6 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	148.6 W	299.4 W	448.4 W	595.8 W	743.1 W
% Max Load	19.8%	39.9%	59.8%	79.4%	99.1%
Room Temp.	43.2° C	42.9° C	45.7° C	48.0° C	48.3° C
PSU Temp.	47.7° C	47.8° C	48.2° C	49.2° C	53.4° C
Voltage Regulation	Pass	Pass	Pass	Pass	Pass
Ripple and Noise	Pass	Pass	Pass	Pass	Pass
AC Power	167.4 W	331.8 W	503.9 W	684.0 W	868.0 W
Efficiency	88.8%	90.2%	89.0%	87.1%	85.6%
AC Voltage	114.5 V	112.8 V	110.0 V	108.8 V	106.6 V
Power Factor	0.974	0.991	0.995	0.997	0.998
Final Result	Pass	Pass	Pass	Pass	Pass

The Thermaltake Toughpower Grand 750 W can really deliver its labeled wattage at high temperatures.

Efficiency was extremely high, above 88% at light load (20% load, 150 W) and above 85% at full load, peaking 90.2% at 40% load (300 W). These are good results but since it is an 80 Plus Gold unit, it should present efficiency above 87% at full load. Time and time again we see this happening, because the 80 Plus certification tests are done at a room temperature of only 23° C, while we tested this particular unit at 48° C, and efficiency drops with temperature.

Voltages were always inside the allowed range, but during tests four and five the +5 V and +3.3 V outputs were touching the lower limit (+4.75 V and +3.13 V, respectively).

Noise and ripple levels were always extremely 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 and +3.3 V outputs. All values are peak-to-peak figures.

Figure 19: +12VA input from load tester during test five at 743.1 W (21.4 mV)

Figure 20: +12VB input from load tester during test five at 743.1 W (49.6 mV)

Figure 21: +5V rail during test five at 743.1 W (11.4 mV)

Figure 22: +3.3 V rail during test five at 743.1 W (19.6 mV)

Let’s see if we can pull even more from the Thermaltake Toughpower Grand 750 W.

[nextpage title=”Overload Tests”]

Below you can see the maximum we could pull from this power supply. If we tried to pull more than listed the unit would shut down, which is the desirable behavior. During this test noise and ripple continued to be at very low levels, but the +3.3 V output dropped to +3.07 V, below the minimum allowed. Efficiency was still above 84%.

Input	Overload Test
+12VA	33 A (396 W)
+12VB	33 A (396 W)
+5V	10 A (50 W)
+3.3 V	10 A (33 W)
+5VSB	3 A (15 W)
-12 V	0.5 A (6 W)
Total	882.6 W
% Max Load	117.7%
Room Temp.	49.2° C
PSU Temp.	53.7° C
AC Power	1,048 W
Efficiency	84.2%
AC Voltage	105.9 V
Power Factor	0.998

[nextpage title=”Main Specifications”]

The specs of the Thermaltake Toughpower Grand 750 W include:

• Standards: ATX12V 2.3 and EPS12V 2.92
• Nominal labeled power: 750 W
• Measured maximum power: 882.6 W at 49.2° C ambient
• Labeled efficiency: up to 90%, 80 Plus Gold certification
• Measured efficiency: Between 85.6% and 90.2% at 115 V (nominal, see complete res
  ults for actual voltage)
• Active PFC: Yes
• Modular Cabling System: Yes
• Motherboard Power Connectors: One 20/24-pin connector, one EPS12V connector, and two ATX12V connectors that together form an EPS12V connector
• Video Card Power Connectors: Two six-pin connectors and two eight-pin connectors on separate cables, two eight-to-six-pin adapters included
• SATA Power Connectors: Eight on two cables
• Peripheral Power Connectors: Eight on two cables
• Floppy Disk Drive Power Connectors: One
• Protections (as listed by the manufacturer): Over voltage (OVP), under voltage (UVP), over power (OPP/OLP), over current (OCP), over temperature (OTP), and short-circuit (SCP) protections
• Are the above-listed protections really present?: Yes
• Warranty: Seven years
• Real Manufacturer: CWT
• More Information: https://thermaltakeusa.com
• Average price in the US*: USD 190.00

* Researched at Google products on the day we published this review.

[nextpage title=”Conclusions”]

The new Thermaltake Toughpower Grand 750 W is a good power supply. During our tests it achieved very high efficiency, peaking above 90%, extremely low noise and ripple levels, and an adequate number of connectors for a 750 W product. Due to its highly overspec’ed components, we could easily pull 880 W from it.

However, compared to other 80 Plus Gold power supplies, it is not the best game in town. On the technical side, the +3.3 V and +5 V outputs, though inside the allowed range, dropped too much when we pulled 600 W and above, touching the lower limit. Competing products have a better voltage regulation.

But what will probably kill Toughpower Grand 750 W is its price, which comes with a suggested price of USD 200 in the US. It can be found on the market on the USD 180-200 range, and at this range you can buy 850 W 80 Plus Gold power supplies, like the OCZ Z Series 850 W (USD 175), NZXT HALE90-850-M (USD 180), and Corsair AX850W (USD 190). So, unless Thermaltake drops the price of the Toughpower Grand 750 W below USD 160, we think that you will be doing a better selection by picking any of these other three competing products.