ocaholic - PSUs > Fractal Design Integra R2 750W Review

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Photo Gallery

Page 2 - Photo Gallery

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Delivery and Specifications

As noted earlier, the Fractal Design Integra R2 750W is a non-modular PSU, which means that all the cables are permanently attached to the PSU, which makes the life a bit harder if you are looking to make a clean PC setup.

Cables
Cable	Length
1 x ATX 20+4 pin	52 cm
1 x EPS/ATX 12V (4+4) pin	66 cm
2x PCI-E 6+2 + 6+2 pin	52, 59 cm
1 x 3x SATA	56, 70, 84 cm
1 x 3x SATA	36, 50, 64 cm
1 x 2x Molex + 1x Floppy	55, 68, 71 cm

The connectivity is pretty decent for a 750W PSU as it packs enough power and connectors for multi-GPU configuration, featuring a total of four PCI-Express 6+2-pin power connectors as well as a bunch of others for peripherals, including a total of six SATA, two Molex and single 4-pin Floppy connector. Although most peripheral and accessory devices tend to rely on SATA power connectors these days, we would really like to see a bit more Molex connectors on Fractal Design R2 750W. The cables are 18 AWG. High end PSUs normaly use better 16AWG or even better.

Specifications
Voltage	Current	Power
+ 3.3 V	25 A	150 Watt	750 Watt (Total)
+ 5.0 V	20 A	150 Watt
+ 12 V	56 A	672 Watt
- 12 V	0.3 A	3.6 Watt
+ 5 Vsb	3.0 A	15 Watt

The Fractal Integra 750 does not use a single +12V rail design but a two rail design. It should be taken into an account that it actually provides 55Amps on both rails combined. When there is load on only one rail the Integra 750W is capable of delivering 30Amps on 12V1 and 30Amps on 12V2. Most PSU makers are currently going back to the single +12V rail design, but this design also does not represent a big problem unless you are pushing for extreme multi-GPU setups that require much higher-end PSUs.

The Integra R2 750W has been 80Plus Bronze certified. This means, that the efficiency of this PSU should be above 82% at 20% load, above 85% at 50% load and above 82% at 100% load.

As you can see from the list below, the rest of the features include standard protections and a 3-year warranty which is pretty much what you get with a mid-range class PSU.

80Plus Bronze
OVP, UVP, OCP, SCP, OPP, OTP
Dimensions (W x H x D): 150 mm x 86 mm x 140 mm
120 millimeter fan
Warranty: 3 Years
Price: 100 CHF

Page 3 - Delivery / Specs

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A Look Inside

Fractal Design's Integra R2 750W is based on a HEC OEM design.

On the primary side you find a rectifier. We can find a PCB housing the FAN4800. The FAN4800 controls the PFC Booster and the Push-Pull converter. This PSU has a Push-Pull topology using two Mosfets and two Diodes according to the following primary sided principle: link

This is an old school standard topology; simple and proven, but it will not achieve any new efficiency records. Because this topology requires hard switching from the Mosfets (Switching Mosfets under voltage and current generates losses) this topology is more and more replaced in the PC PSU market by resonant topologies. The transformer has on the secondary side two coils one for 12V and one for 5V. 3.3V is generated from the 5V Coil. This is the classic old PSU topology.

The APFC Capacitor with 470uF at 400V and 85°C from Teapo. The PFC Booster uses a BCY10-600 Hyperfast recovery diode and 3 60R190C6 Mosfets. This is ok for a PSU in this price range; SiC Diodes are still quite expensive. For rectifying the secondary side Schottky diodes are used. The Output filter Capacitors are from Teapo. 105°C is written on them.

The OCP, UVP, OVP is done by a WT7527.

Page 4 - A Look Inside

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Input/Output Power and Efficiency

Page 5 - Input/Output Power and Efficiency

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Result Analysis and Discussion

Efficiency 115V
Load	Pin(W)	Pout(W)	Efficiency
20 %	178.8	152.6	85.32 %
50 %	439.1	378.4	86.18 %
100 %	903.3	743.8	82.34 %

The 80Plus Bronze certification requirements (82% - 85% - 82%) are surpassed especially at 20% Load. This is the case with most of todays PSU's an it mainly originates from the reason of lower losses in the AC filtering stage and the PFC at 230V AC.

Output Stability
Load	Rail	Loading(A)	Output(V)
20 %	5V	1.61	5.40
	3.3V	1.58	3.33
	12V	9.91	12.06
	5VSB	1.00	5.08

50 %	5V	2.97	5.02
	3.3V	2.90	3.34
	12V	26.57	11.98
	5VSB	1.54	5.03

100 %	5V	5.10	5.02
	3.3V	5.11	3.25
	12V	54.02	11.86
	5VSB	3.00	4.97

The stability of the output voltages and the outcome of the crossload tests (results not shown here) are not perfect but still with margin within the norms and absolutely satisfactory (especially when you consider the Topology used in this PSU).

Noise
Load
20 %	Silent
50 %	Audible
100 %	Noisy

Noise level results are decent but we would prefer if it was much less noisy under full load.

Noise/Ripple
Voltage	Noise/Ripple Vpp
5V	0.031
12V	0.050
-12V	0.032
3.3V	0.032
+5VSB	0.026

The noise values are within the ATX norm. This is a perfect example for the quality difference between Japanese and non Japanese capacitors. The topology used in this PSU is filter friendly and Teapo capacitors are used in a high amount. However the filter performance is worse compared to high end PSUs using Japanese capacitors. Transient loads are a big issue for this topology. In modern PCs transient load changes often occur. This can end in a output Voltage not within the norm for a short moment. This again can end up in system instability.

Page 6 - Result Analysis and Discussion