[nextpage title=”Introduction”]
The Fractal Design Integra R2 is available in 500 W, 650 W, and 750 W versions, all with the 80 Plus Bronze certification. Let’s take a look at the 750 W model, which comes with a very nice price tag.
This power supply is manufactured by HEC, being a rebranded HEC-750TB. This is the same platform used by the Cougar CMX V2 700 W. The only difference between the two are the +12 V rectifiers, which are “stronger” on the Fractal Design Integra R2 750 W and the use, on the Cougar CMX V2 700 W, of a Japanese capacitor on the primary and a modular cabling system.
Figure 1: Fractal Design Integra R2 750 W power supply
Figure 2: Fractal Design Integra R2 750 W power supply
The Fractal Design Integra R2 750 W is 5.5” (140 mm) deep, using a 120 mm sleeve bearing fan on its bottom (Hong Sheng A1335M12S).
Figure 3: Fan
This unit doesn’t have a modular cabling system. All cables use nylon sleeves that come from inside the unit. This power supply comes with the following cables:
- Main motherboard cable with a 20/24-pin connector, 20.5” (52 cm) long
- One cable with two ATX12V connectors that together form an EPS12V connector, 26” (66 cm) long
- Two cables, each with two six/eight-pin connectors for video cards, 20.5” (52 cm) to the first connector, 2.8” (7 cm) between connectors
- One cable with three SATA power connectors, 22” (56 cm) to the first connector, 5.5” (14 cm) between connectors
- One cable with three SATA power connectors, 14.2” (36 cm) to the first connector, 5.5” (14 cm) between connectors
- One cable with two standard peripheral power connectors and one floppy disk drive power connector, 21.6” (55 cm) to the first connector, 5.1” (13 cm) between connectors
All wires are 18 AWG, which is the correct gauge to be used.
The cable configuration is compatible with a mainstream 750 W unit.
Figure 4: Cables
Let’s now take an in-depth look inside this power supply.
[nextpage title=”A Look Inside the Fractal Design Integra R2 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.
On this page we will have an overall look, while in the following pages we will discuss in detail the quality and ratings of the components used.
Figure 5: Top view
Figure 6: Front quarter view
Figure 7: Rear quarter view
Figure 8: The 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.
In this power supply, this stage is flawless. It has one X capacitor, two Y capacitors, and one ferrite coil more than the minimum required.
Figure 9: Transient filtering stage (part 1)
Figure 10: Transient filtering stage (part 2)
On the next page, we will have a more detailed discussion about the components used in the Fractal Design Integra R2 750 W.
[nextpage title=”Primary Analysis”]
On this page, we will take an in-depth look at the primary stage of the Fractal Design Integra R2 750 W. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.
This power supply uses one GBJ1506 rectifying bridge, attached to the same heatsink as the active PFC transistors. This component supports up to 15 A at 100° 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.
Figure 11: Rectifying bridge
The active PFC circuit uses three IPP60R190C6 MOSFETs, each supporting up to 20.2 A at 25° C or 12.8 A at 100° C in continuous mode (note the difference temperature makes), or 59 A in pulse mode at 25° C. These transistors present a 190 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.
Figure 12: Active PFC transistors and diode
The output of the active PFC circuit is filtered by one 470 µF x 400 V electrolytic capacitor, from Teapo, labeled at 105° C.
Figure 13: Capacitor
In the switching section, two IPP60R190E6 MOSFETs are used in the traditional two-transistor forward configuration. The specifications for these transistors are the same as for the active PFC transistors.
Figure 14: One of the switching transistors
The primary is controlled by an FAN4800 active PFC/PWM combo controller.
Figure 15: Active PFC/PWM combo controller
Let’s now take a look at the secondary of this power supply.
[nextpage title=”Secondary Analysis”]
The Fractal Design Integra R2 750 W has eight Schottky rectifiers attached to the secondary heatsink.
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 PFR40L60CT Schottky rectifiers (40 A, 20 A per internal diode at 110° C, 0.65 V maximum voltage drop), giving us a maximum theoretical current of 114 A or 1,371 W for this output.
The +5 V output uses two SBR30A40CT Schottky rectifiers (30 A, 15 A per internal diode at 110° C, 0.50 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 SBR30A40CT Schottky rectifiers, giving us a maximum theoretical current of 43 A or 141 W for this output.
Figure 16: The +3.3 V, +5 V, and +12 V rectifiers
This power supply uses a PS223 monitoring integrated circuit, which supports over voltage (OVP), under voltage (UVP), over current (OCP), and over temperature (OTP) protections. This chip has four OCP channels, one for +3.3 V, one for +5 V, and two for +12 V, correctly matching the number of +12 V rails advertised by the power supply manufacturer (two).
Figure 17: Monitoring circuit
The electrolytic capacitors available in the secondary are from Teapo, and are labeled at 105° C.
Figure 18: Capacitors
[nextpage title=”The +5VSB Power Supply”]
The +5VSB (a.k.a. standby) power supply is independent of the main power supply, since it is on continuously.
On the Fractal Design Integra R2 750 W, the +5VSB power supply uses a TNY279PN integrated circuit, which incorporates the PWM controller and the switching transistor in a single chip.
Figure 19: The +5VSB integrated circuit with an integrated switching transistor
The rectification of the +5VSB output is performed by an SBL1040CT Schottky rectifier, which supports up to 10 A (5 A per internal diode at 95° C, 0.55 V maximum voltage drop).
Figure 20: The +5VSB rectifier
[nextpage title=”Power Distribution”]
In Figure 21, you can see the power supply label containing all the power specs.
Figure 21: Power supply label
This power supply is sold as having two +12 V rails, which is correct, since this unit has two +12 V over current protection channels. Click here to understand more about this subject.
The two +12 V rails are distributed as follows:
- +12V1 (solid yellow wire): Main motherboard cable, the SATA and peripheral connectors, and one of the video card power cables
- +12V2 (yellow/blue wires): The ATX12V/EPS12V cable and one of the video card power cables
When using only one video card, it is important to use the video card power cable that has solid yellow wires. Otherwise, you will have your video card installed on the same rail as your CPU, which may trigger the power supply’s over current protection.
How much power can this unit really deliver? Let’s find out.
[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 this test, the +12VA input was connected to the power supply’s +12V1 rail, while the +12VB input was connected to the power supply’s +12V2 rail.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 5.5 A (66 W) | 11.5 A (138 W) | 17 A (204 W) | 22.5 A (270 W) | 28.5 A (342 W) |
| +12VB | 5.5 A (66 W) | 11 A (132 W) | 16.5 A (198 W) | 22 A (264 W) | 28.5 A (342 W) |
| +5 V | 1 A (5 W) | 2 A (10 W) | 4 A (20 W) | 6 A (30 W) | 8 A (40 W) |
| +3.3 V | 1 A (3.3 W) | 2 A (6.6 W) | 4 A (13.2 W) | 6 A (19.8 W) | 8 A (26.4 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 | 150.3 W | 296.9 W | 444.8 W | 589.4 W | 747.4 W |
| % Max Load | 20.0% | 39.6% | 59.3% | 78.6% | 99.7% |
| Room Temp. | 45.5° C | 44.8° C | 45.8° C | 48.2° C | 49.4° C |
| PSU Temp. | 50.0° C | 49.9° C | 50.4° C | 52.5° C | 56.0° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 175.5 W | 342.8 W | 519.2 W | 703.0 W | 923.0 W |
| Efficiency | 85.6% | 86.6% | 85.7% | 83.8% | 81.0% |
| AC Voltage | 117.2 V | 115.7 V | 114.2 V | 112.1 V | 110.0 V |
| Power Factor | 0.979 | 0.99 | 0.994 | 0.995 | 0.996 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
The Fractal Design Integra R2 750 W passed our tests.
The 80 Plus Bronze certification promises efficiency of at least 82% under light (i.e., 20%) load, 85% under typical (i.e., 50%) load, and 82% under full (i.e., 100%) load. During our tests, the Fractal Design Integra R2 750 W was not able to present 82% efficiency at full load. However, we have to consider that we tested this power supply at almost 50° C, while the 80 Plus certification tests are conducted at 23° C, and efficiency drops as temperature increases. Another explanation for the lower efficiency is because of the AC voltage, which was below 115 V during this particular test. On the other hand, we have excellent efficiency numbers for the other tests, in particular at light load, where we saw 85% efficiency.
Let’s discuss voltage regulation on the next page.
[nextpage title=”Voltage Regulation Tests”]
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. We consider a power supply as “flawless” if it shows voltages within 3% of its nominal values. In the table below, you can see the power supply voltages during our tests and, in the following table, the deviation, in percentage, of their nominal values.
The Fractal Design Integra R2 750 W presented very good voltage regulation for a mainstream unit.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | +11.94 V | +11.88 V | +11.84 V | +11.75 V | +11.65 V |
| +12VB | +11.94 V | +11.87 V | +11.81 V | +11.71 V | +11.60 V |
| +5 V | +5.04 V | +5.02 V | +4.99 V | +4.96 V | +4.93 V |
| +3.3 V | +3.29 V | +3.27 V | +3.25 V | +3.22 V | +3.19 V |
| +5VSB | +4.97 V | +4.94 V | +4.91 V | +4.87 V | +4.82 V |
| -12 V | -11.47 V | -11.57 V | -11.65 V | -11.72 V | -11.81 V |
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | -0.50% | -1.00% | -1.33% | -2.08% | -2.92% |
| +12VB | -0.50% | -1.08% | -1.58% | -2.42% | -3.33% |
| +5 V | 0.80% | 0.40% | -0.20% | -0.80% | -1.40% |
| +3.3 V | -0.30% | -0.91% | -1.52% | -2.42% | -3.33% |
| +5VSB | -0.60% | -1.20% | -1.80% | -2.60% | -3.60% |
| -12 V | 4.62% | 3.72% | 3.00% | 2.39% | 1.61% |
Let’s discuss the ripple and noise levels on the next page.
[nextpage title=”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 Fractal Design Integra R2 750 W provided low ripple and noise levels, as you can see in the table below.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | |
| +12VA | 26.0 mV | 27.0 mV | 32.8 mV | 41.8 mV | 60.6 mV |
| +12VB | 22.6 mV | 25.4 mV | 30.6 mV | 36.4 mV | 51.8 mV |
| +5 V | 10.2 mV | 12.2 mV | 14.8 mV | 17.6 mV | 21.4 mV |
| +3.3 V | 16.8 mV | 18.6 mV | 21.8 mV | 23.4 mV | 26.2 mV |
| +5VSB | 26.4 mV | 26.2 mV | 29.0 mV | 32.0 mV | 40.4 mV |
| -12 V | 48.4 mV | 47.4 mV | 50.6 mV | 52.8 mV | 52.4 mV |
Below you can see the waveforms of the outputs during test five.
Figure 22: +12VA input from load tester during test five at 747.4 W (60.6 mV)
Figure 23: +12VB input from load tester during test five at 747.4 W (51.8 mV)
Figure 24: +5V rail during test five at 747.4 W (21.4 mV)
Figure 25: +3.3 V rail during test five at 747.4 W (26.2 mV)
Let’s see if we can pull more than 750 W from this unit. [nextpage title=”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. The maximum we could pull from this power supply is listed below. During this test, ripple and noise levels were still low, and voltages were still within their allowed range.
| Input | Overload Test |
| +12VA | 31 A (372 W) |
| +12VB | 31 A (372 W) |
| +5 V | 18 A (90 W) |
| +3.3 V | 18 A (59.4 W) |
| +5VSB | 3 A (15 W) |
| -12 V | 0.5 A (6 W) |
| Total | 889.4 W |
| % Max Load | 118.6% |
| Room Temp. | 47.4° C |
| PSU Temp. | 52.7° C |
| AC Power | 1,145 W |
| Efficiency | 77.7% |
| AC Voltage | 106.3 V |
| Power Factor | 0.998 |
[nextpage title=”Main Specifications”]
The main specifications for the Fractal Design Integra R2 750 W power supply include:
- Standards: ATX12V 2.31
- Nominal labeled power: 750 W at 40° C
- Measured maximum power: 889.4 W at 47.4° C
- Labeled efficiency: 80 Plus Bronze certification
- Measured efficiency: Between 81.0% and 86.6%, at 115 V (nominal, see complete results for actual voltage)
- Active PFC: Yes
- Modular Cabling System: No
- Motherboard Power Connectors: One 20/24-pin connector and two ATX12V connectors that together form an EPS12V connector
- Video Card Power Connectors: Four six/eight-pin connectors on two cables
- SATA Power Connectors: Six on two cables
- Peripheral Power Connectors: Two on one cable
- Floppy Disk Drive Power Connectors: One
- Protections (as listed by the manufacturer): NA
- Are the above protections really available? The power supply has over voltage (OVP), under voltage (UVP), over current (OCP), over power (OPP), and short-circuit (SCP) protections.
- Warranty: Three years
- More Information: https://www.fractal-design.com
- MSRP in the US: USD 80.00
[nextpage title=”Conclusions”]The Fractal Design Integra R2 750 W proved to be an excellent mainstream power supply, with very good efficiency, voltage regulation, and ripple and noise levels for a product targeted at this segment, at an unbeatable price (USD 80). One of the highlights of this power supply is its depth. It is only 5.5” (140 mm) deep, fitting some small form factor (SFF) cases that require power supplies with this dimension.
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