Corsair Professional Series AX760 and AX860 review

1. Introduction2. Corsair AX760 (Bundle & Cables)3. Corsair AX760 (External)4. Corsair AX760 (Internal)5. Corsair AX760 (Super High Res Gallery)6. Corsair AX860 (Bundle & Cables)7. Corsair AX860 (External)8. Corsair AX860 (Internal)9. Corsair AX860 (Super High Res Gallery)10. Corsair AX760 (Testing Methodology & Results)11. Corsair AX860 (Testing Methodology & Results)12. Closing Thoughts13. View All Pages

Corsair have been active lately, not only have they recently unleashed a new range of liquid coolers, but they have introduced two completely new power supply families. We have already reviewed the AX760i and AX860i ‘digital' supplies, a formidable design in collaboration with Flextronics. Today we are analysing the latest AX760 and AX860 units, both Platinum certified modular units at a more affordable price point. Are they worthy of a purchase?

There is no doubt that the AX760i and AX860i are spectacular power supplies, however they are rather expensive. Corsair have released the new non ‘i' supplies to target a slightly wider audience, charging around £20 less per unit. If you have no interest in the Corsair LINK interface module and accompanying software it may be a good way to keep a little extra cash in the bank.

The AX760 and AX860 are certainly not budget power supplies. Corsair have teamed up with market leader Seasonic to introduce the highest quality products for the enthusiast user. These are fully modular designs which have achieved 80 Plus Platinum Certification. The designs incorporate a hybrid fan controller which offers a ‘zero RPM' mode at up to around 70% of load (if room ambient is maintained at around 25c). The company have adopted Sanyo Denki fans in both supplies, premium quality units.

Corsair AX760 Overview:

• 63 Amp Single +12V rail
• 80 PLUS PLATINUM Efficiency
• Ultra Low Noise Fan Control with Zero RPM Mode
• ZVS technology
• 3.3V & 5V DC-DC and Independent DC Connector board
• Premium Quality Components & Double-Sided PCB
• Fully Modular Cable System
• Industrial-grade protection, including OCP on the +12V rail
• Seven Year Warranty

Corsair AX860 Overview:

• 71 Amp Single +12V rail
• 80 PLUS PLATINUM Efficiency
• Ultra Low Noise Fan Control with Zero RPM Mode
• ZVS technology
• 3.3V & 5V DC-DC and Independent DC Connector board
• Premium Quality Components & Double-Sided PCB
• Fully Modular Cable System
• Industrial-grade protection, including OCP on the +12V rail
• Seven Year Warranty

Corsair always create fantastic box artwork, and the AX760 is no exception. An artistic view of the top of the power supply is blended into a dark, moody composition.

The power supply is shipped protected inside soft foam. Accessories are safely shipped beside and on top of the actual unit. The bundle includes a user manual, warranty information (seven years), cable ties, case badge and regional specific power plug.

The AX760 is shipped carefully protected inside a reusable felt bag. This is to protect the paintwork against any minor scuffing during shipping.

The Corsair AX760 is a completely modular design and there are no hardwired cables attached to the chassis. Bonus points for this.

Above is a list of the modular cables supplied with the Corsair AX760 power supply. Corsair have included six 6+2 PCI-E cables, identical to the AX760i design reviewed previously. The main ATX/EPS and PCIE cables are fully sleeved, with the peripheral cables all being the flat ‘ribbon' style to help maximise airflow.

Corsair power supplies are really a lesson in design. The plain black paint is both deep and resilient to fingerprints and minor surface damage. The two tone colour scheme  of the ‘AX760' is appealing and very attractive.

The large 120mm fan is hidden behind a black grill, with the Corsair brand name proudly presented in the center. We will have a closer look at this when we open the chassis later in the review.

The side of the chassis is honeycomb vented to help improve air flow around the components. At the side is a power switch and connector.

The modular panel takes up the full width of the power supply and is carefully labelled to help with the installation phase of the system build. At the top corner is a ‘hybrid' switch which can be set to temperature controlled ‘hybrid' or the active ‘normal' setting. Hybrid ensures that the fan will remain inactive as long as possible – Corsair claim up to 70% load in a room @ 25c ambient.

The Corsair AX760 can deliver 63A from the single +12V rail for 756W of the total power. This is more than enough to handle a high end SLi or Crossfire system build. Total power is rated to 760 Watts @ 50c ambient temperature.

The Corsair AX760 power supply uses a premium grade San Ace 120 ‘9s1212f404' fan. This is a Sanyo Denki unit which incorporates dual ball bearings. We have seen this fan incorporated into many Seasonic designs recently and there really is no better a fan on the market today for this environment.

As mentioned earlier this is a Seasonic design and the soldering quality throughout is excellent and the layout is very clean, with several rows of thin heatinks across the PCB to help the thermal curve. This power supply uses a high quality dual sided PCB providing key advantages over standard PCB layouts. They can use double the copper for traces and return planes for instance. This in turn can increase efficiency as a result of lower resistive losses and helps enhance cooling proficiency.

The AX760 uses hole soldering to help improve reliability when using a double sized PCB design.

The +3.3V and +5V voltage regulators have been from the main PCB to a modular DC connector board which attaches to the front of the enclosure. The design comprises two coils, two X caps, two Y caps and a MOV. Inside are high grade 105c Nippon Chemi Con capacitors. The secondary stage also uses a mixture of solid polymer and electrolytic capacitors.

The AX760 utilises LLC resonant switching technology to switch at zero voltage, increasing efficiency and reducing heat. Over-Current Protection (OCP) is present on all rails, including the single +12V rail. Over-Temperature Protection (OTP) and Short-Circuit Protection (SCP) are both also included.

On this page we present some super high resolution images of the product taken with the 24.5MP Nikon D3X camera and 24-70mm ED lens. These will take much longer to open due to the dimensions, especially on slower connections. If you use these pictures on another site or publication, please credit Kitguru.net as the owner/source.

The box is identical to the AX760, except for the model name (obviously!).

The power supply is shipped protected inside soft foam. Accessories are safely shipped beside and on top of the actual unit. The bundle includes a user manual, warranty information (seven years), cable ties, case badge and regional specific power plug.

The AX860 is shipped inside a soft felt bag to offer some protection against scuffing during transit.

The Corsair AX760 is a completely modular design and there are no hardwired cables attached to the chassis.

Above is a list of the modular cables supplied with the Corsair AX860 power supply. Corsair have included six 6+2 PCI-E cables, identical to the AX860i design reviewed previously. The main ATX/EPS and PCIE cables are fully sleeved, with the peripheral cables all being the flat ‘ribbon' style to help maximise airflow.

For reference, this is the same as the AX760 which we looked at earlier in the review.

Corsair power supplies are really a lesson in design. The plain black paint is both deep and resilient to fingerprints and minor surface damage. The two tone colour scheme  of the ‘AX860' is appealing and very attractive.

The large 120mm fan is hidden behind a black grill, with the Corsair brand name proudly presented in the center. We will have a closer look at this when we open the chassis later in the review.

The product name next to a power switch and connector. The rest of this panel is vented for airflow.

The modular panel takes up the full width of the power supply and is carefully labelled to help with the installation phase of the system build. At the top corner is a ‘hybrid' switch which can be set to temperature controlled ‘hybrid' or the active ‘normal' setting. Hybrid ensures that the fan will remain inactive as long as possible – Corsair claim up to 70% load in a room @ 25c ambient.

The Corsair AX860 can deliver 71A from the single +12V rail for 852W of the total power. This is more than enough to handle a high end SLi or Crossfire system build. Total power is rated to 860 Watts @ 50c ambient temperature.

The Corsair AX860 power supply uses a premium grade San Ace 120 ‘9s1212f404' fan. This is a Sanyo Denki unit which incorporates dual ball bearings. We have seen this fan incorporated into many Seasonic designs recently and there really is no better a fan on the market today for this environment. This is the same high grade fan as the one used in the AX760.

This is a Seasonic design and the soldering quality throughout is excellent and the layout is very clean, with several rows of thin heatinks across the PCB to help the thermal curve. This power supply uses a high quality dual sided PCB providing key advantages over standard PCB layouts. They can use double the copper for traces and return planes for instance. This in turn can increase efficiency as a result of lower resistive losses and helps enhance cooling proficiency.

The AX860 uses hole soldering to help improve reliability when using a double sized PCB design.

The +3.3V and +5V voltage regulators have been from the main PCB to a modular DC connector board which attaches to the front of the enclosure. The design comprises two coils, two X caps, two Y caps and a MOV. Inside are high grade 105c Nippon Chemi Con capacitors (420v 390 uF each). The secondary stage also uses a mixture of solid polymer and electrolytic capacitors.

The AX760 utilises LLC resonant switching technology to switch at zero voltage, increasing efficiency and reducing heat. Over-Current Protection (OCP) is present on all rails, including the single +12V rail. Over-Temperature Protection (OTP) and Short-Circuit Protection (SCP) are both also included.

On this page we present some super high resolution images of the product taken with the 24.5MP Nikon D3X camera and 24-70mm ED lens. These will take much longer to open due to the dimensions, especially on slower connections. If you use these pictures on another site or publication, please credit Kitguru.net as the owner/source.

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
• Extech digital sound level meter
• Digital oscilloscope (20M S/s with 12 Bit ADC)
• Variable Autotransformer, 1.4 KVA

DC Output Load Regulation
Combined DC Load	+3.3V		+5V		+12V		+5VSB		-12V
	A	V	A	V	A	V	A	V	A	V
75W	1.27	3.34	1.22	5.05	4.95	12.07	0.50	5.04	0.20	-12.05
150W	2.17	3.33	2.87	5.04	10.07	12.07	1.00	5.04	0.30	-12.05
375W	6.17	3.33	6.05	5.03	26.15	12.06	1.50	5.03	0.50	-12.06
565W	10.36	3.33	10.87	5.02	38.32	12.05	2.00	5.03	0.60	-12.07
760W	10.78	3.32	13.92	5.02	54.05	12.04	3.00	5.02	0.80	-12.08

Regulation is as good as we have seen, holding steady across all the rails. The +3.3V and +5V rail hardly moved at all, regardless of the load

Corsair AX760	Maximum Load
	902W

We managed to push this supply to 902W before it would shut down safely. It is clearly over specified for the wattage rating.

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
734W	1.0	3.33	1.0	5.05	60.0	12.03	0.2	-12.05	0.50	5.03
154W	15.0	3.32	15.0	5.02	2.0	12.07	0.2	-12.05	0.50	5.03

The Corsair AX760 delivered class leading results. We hit the power supply with 60A on the +12V rail and it held at 12.03v. Other rails also exhibited fantastic results.

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	10
150W	10	10	20	15
375W	15	15	25	15
565W	15	15	35	15
760W	20	15	35	20

Ripple suppression is very good, holding the +12V rail at full load @ 35mV, well within industry specifications. Other rails are also held well within industry tolerance guidelines.

Efficiency (%)
75W	86.95
150W	92.41
375W	93.92
565W	92.45
760W	91.77

Efficiency of the power supply peaked close to 94 percent at 50 percent load, dropping to just under 92 percent efficiency at full load. Excellent results.

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 Digital Sound Level Noise Decibel Meter Style 2 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 Refrigerator
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
375W	<28.0
565W	31.7
760W	33.4

This power supply is very quiet in Hybrid mode, with the fan only spinning up once we hit around 430W load. Even around 600W load it was barely audible. The high grade 120mm fan really helps maintain a very low acoustic curve.

Temperature (c)
	Intake	Exhaust
75W	36	41
150W	38	44
375W	39	47
565W	45	54
760W	47	58

Exhaust temperatures are excellent, reaching a maximum delta of +11c above intake ambient.

Maximum load	Efficiency
902W	89.44

For those interested, we measured efficiency when stressing the unit to breaking point. 89.44 percent efficiency at 902W … hardly practical, but interesting regardless.

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
• Extech digital sound level meter
• Digital oscilloscope (20M S/s with 12 Bit ADC)
• Variable Autotransformer, 1.4 KVA

DC Output Load Regulation
Combined DC Load	+3.3V		+5V		+12V		+5VSB		-12V
	A	V	A	V	A	V	A	V	A	V
100W	1.57	3.35	1.79	5.05	6.66	12.08	0.50	5.05	0.20	-12.03
225W	3.74	3.34	3.88	5.05	15.58	12.08	1.00	5.05	0.20	-12.04
450W	7.54	3.34	8.35	5.04	30.77	12.07	1.50	5.04	0.30	-12.05
675W	11.32	3.34	12.37	5.04	47.46	12.06	2.00	5.03	0.50	-12.05
860W	1.61	3.33	1.17	5.03	65.01	12.05	0.50	5.03	0.20	-12.07

Load regulation is excellent, holding to almost reference figures across the range of load settings. An excellent set of results.

Corsair AX860	Maximum Load
	1011W

We managed to push the PSU to achieve 1011W before it would shut down, delivering around 151W more than rated specifications. These units are very over specified for the rating.

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
760W	1.0	3.35	1.0	5.05	60.0	12.06	0.2	-12.05	0.50	5.05
165W	15.0	3.33	18.0	5.03	2.0	12.08	0.2	-12.06	0.50	5.04

The Corsair AX860 exhibited no problems when dealing with our intensive Cross Loading test. It was tasked with 60A on the +12V rail and it held at 12.06V.

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
100W	10	10	15	10
225W	10	10	20	15
450W	15	15	30	15
675W	15	15	35	15
860W	20	15	40	20

Noise suppression results are excellent, peaking at 40mV on the +12V rail when under full load. The other rails fell between 10mV and 20mV across the full range of loads. Well within industry tolerance specifications.

Efficiency (%)
100W	87.23
225W	92.44
450W	93.97
675W	92.52
860W	91.69

Efficiency is excellent, peaking at almost 94 percent at 50 percent load. Efficiency falls down to around 91.7% 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 Digital Sound Level Noise Decibel Meter Style 2 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 Refrigerator
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)
100W	<28.0
225W	<28.0
450W	<28.0
675W	31.9
860W	33.9

The fan is disabled at the lower power levels under ‘Hybrid' mode. At around 600W output the fan spins up a little, although until around 700W it is basically inaudible. No complaints with the noise level from the AX860.

Temperature (c)
	Intake	Exhaust
100W	37	44
225W	38	47
450W	43	53
675W	46	57
860W	48	60

Exhaust temperatures are good, thanks to the efficiency of the unit at lower power levels, even with the fan disabled. At close to full load the fan spins up a little, which reduces the temperatures.

Maximum load	Efficiency
1011 watts	88.77

At 1011watts, the efficiency level measures 88.77%. Not a practical situation to be running 24/7, but worth noting.

The Corsair Professional Series AX760 and AX860 power supplies are both excellent units which exhibit no weaknesses. They are beautifully constructed and based around an exceptional Seasonic based 80 Plus Platinum internal design.

These units are ideal for the discerning enthusiast user who would like to save a little over the recently released Digital ‘i' supplies which feature the Corsair LINK interface module and proprietary software. The AX760 and AX860 are around £20 less expensive than the equal wattage ‘i' series units. All models feature exemplary build quality and deep paint work which proves resilient against fingerprints and ham fisted handling.

As our testing has highlighted, both units when pushed hard will deliver much more wattage than their rating suggests. The Corsair AX860 managed to hold a 1000W load for quite some time which highlights that the internal design is pleasingly over specified.

Noise suppression and load regulation are admirable, and both units sailed through the intensive cross loading test without even a minor hiccup. On a technical level there is little to fault from both supplies, in fact finding a closing argument against a purchase proves rather difficult.

There are certainly cheaper options on the market, but in this case you certainly get what you pay for.

The pure modular design will prove popular with a wide audience of case modders who want to fine tune their cabling for ultimate appearance. The high grade 120mm Sanyo Denki fan is very quiet, even when dealing with a very high, active load.

The ‘hybrid' mode will be well suited for the best part of the intended audience, especially enthusiast users wishing to build a system with minimal noise. The fan in both AX760 and AX860 won't spin until the supply is facing at least a 50% load, dependent on the ambient temperature of the system chassis and surrounding environment.

These are excellent power supplies, but to be perfectly honest we expect this now from Corsair, their overall standards in a wide cross section of sectors have been without reproach this year. Both AX760 and AX860 ship with a seven year warranty and they are clearly confident that these units are built to last.

You can pick up the Corsair AX760 and AX860 from Scan for £140 and £152 including vat, respectively.

Pros:

• Rock solid.
• great build quality.
• 7 year warranty.
• low noise.
• ripple suppression.
• load regulation.
• pure modular.
• quiet.

Cons:

• They aren't cheap.

Kitguru says: Corsair are respected as one of the enthusiast user's first choice options. The AX760 and AX860 will further cement their reputation in the upper echelon.

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