Home / Tech News / Featured Tech News / Corsair SF 450 and SF 600 PSU Review

Corsair SF 450 and SF 600 PSU Review

Additional technical assistance: Peter McFarland and Jeremy Price.

Correctly testing power supplies is a complex procedure and KitGuru have configured a test bench which can deliver up to a 2,000 watt DC load. Due to public requests we have changed our temperature settings recently – previously we rated with ambient temperatures at 25C, we have increased ambient temperatures by 10c (to 35c) in our environment to greater reflect warmer internal chassis conditions.

We use combinations of the following hardware:
• SunMoon SM-268
• CSI3710A Programmable DC load (+3.3V and +5V outputs)
• CSI3711A Programmable DC load (+12V1, +12V2, +12V3, and +12V4)
• Extech Power Analyzer
• Extech MultiMaster MM570 digital multimeter
• SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa)
• Digital oscilloscope (20M S/s with 12 Bit ADC)
• Variable Autotransformer, 1.4 KVA

12V output is combined for our testing.

DC Output Load Regulation

Combined

DC Load

+3.3V
+5V
+12V
+5VSB
-12V
A
V
A
V
A
V
A
V
A V
75W
1.09
3.35
1.47
5.04
4.92
12.05
0.50
5.03
0.20
-12.03
150W
2.09
3.35
2.97
5.04
10.02
12.03
0.50
5.02
0.30
-12.03
300W
4.30
3.34
6.00
5.03
20.58
12.02
1.00
5.02
0.30
-12.04
450W
6.57
3.33
8.48
5.01
31.79
12.00
1.50
5.02
0.30
-12.05
600W
9.94
3.33
12.20
5.00
41.78
11.98
2.50
5.01
0.30
-12.06

The Corsair SF600 delivers very good load regulation results.

Corsair SF 600 watt Maximum Load
653W

We managed to get 653W out of the Corsair SF600 before it shut down gracefully.

Next we want to try Cross Loading. This basically means loads which are not balanced. If a PC for instance needs 500W on the +12V outputs but something like 30W via the combined 3.3V and +5V outputs then the voltage regulation can fluctuate badly.

Cross Load Testing +3.3V +5V +12V -12V +5VSB
A V A V A V A V A V
590W 1.0 3.35 1.0 5.03 46.0 11.97 0.2 -12.04 0.50 5.02
145W 12.0 3.33 15.0 5.00 2.0 12.05 0.2 -12.02 0.50 5.03

The supply handled the cross loading tests with flying colours, with minor fluctuation on the +12V rail.

We then used an oscilloscope to measure AC ripple and noise present on the DC outputs. We set the oscilloscope time base to check for AC ripple at both high and low ends of the spectrum. ATX12V V2.2 specification for DC output ripple and noise is defined in the ATX 12V power supply design guide.

ATX12V Ver 2.2 Noise/Ripple Tolerance
Output
Ripple (mV p-p)
+3.3V
50
+5V
50
+12V1
120
+12V2
120
-12V
120
+5VSB
50

Obviously when measuring AC noise and ripple on the DC outputs the cleaner (less recorded) means we have a better end result. We measured this AC signal amplitude to see how closely the unit complied with the ATX standard.

AC Ripple (mV p-p)
DC Load +3.3V +5V +12V 5VSB
75W 10 10 15 5
150W 10 10 20 5
300W 10 10 25 10
450W 15 15 30 10
600W 15 15 30 10

Noise suppression rates as very good, with both +3.3V and +5V rails peaking at 15mV at full load. The +12V rail peaks at 30mV at full load. All well within rated industry parameters.

Efficiency (%)
75W
86.32
150W
88.45
300W
92.21
450W
90.67
600W
88.91

Efficiency peaks at 92.2% percent at 50% load, dropping to around 89% at full load.

We take the issue of noise very seriously at KitGuru and this is why we have built a special home brew system as a reference point when we test noise levels of various components. Why do this? Well this means we can eliminate secondary noise pollution in the test room and concentrate on components we are testing. It also brings us slightly closer to industry standards, such as DIN 45635.

Today to test the Power Supply we have taken it into our acoustics room environment and have set our SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa) one meter away from the unit. We have no other fans running so we can effectively measure just the noise from the unit itself.

As this can be a little confusing for people, here are various dBa ratings in with real world situations to help describe the various levels.

KitGuru noise guide
10dBA – Normal Breathing/Rustling Leaves
20-25dBA – Whisper
30dBA – High Quality Computer fan
40dBA – A Bubbling Brook, or a Refridgerator
50dBA – Normal Conversation
60dBA – Laughter
70dBA – Vacuum Cleaner or Hairdryer
80dBA – City Traffic or a Garbage Disposal
90dBA – Motorcycle or Lawnmower
100dBA – MP3 Player at maximum output
110dBA – Orchestra
120dBA – Front row rock concert/Jet Engine
130dBA – Threshold of Pain
140dBA – Military Jet takeoff/Gunshot (close range)
160dBA – Instant Perforation of eardrum

Noise (dBA)
75W
<28.0
150W
<28.0
300W
<28.0
450W
33.8
600W 36.2

The same fan is used in both SF450 and SF600 power supplies however it has to work harder in the SF600 unit as temperatures rise further above 500 watts load. As such, noise levels are higher, as shown above.

Temperature (c)
Intake
Exhaust
75W
35
39
150W
35
45
300W
37
52
450W
41
58
600W
44
64

The large fan manages to hold a good thermal curve rising to +20c above ambient at full load.

Maximum load
Efficiency
653W
88.2

At 653W the supply drops to 88.2% efficiency. This is not a viable ‘real world’ situation, but its interesting nonetheless.

Become a Patron!

Check Also

Metal Gear Solid and other Konami classics head to PC via GOG

Konami isn’t nearly as active in the video game space as it used to be, …