Hybrid Silent and High Efficiency Gold Metal PSU - CORSAIR AX750W Review

windwithme

windwithme

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In the past 3 years, PSU market competition is on 80Plus.
All brands make own design be more green and get better certificate from 80Plus.
As per 80Plus level, it has platinum, gold, silver and bronze. It bases on energy efficiency.
Of course, this standard is not absolutely. The excellent PSUs also need other features.
I think components are also the key factors.

CORSAIR is a well-known memory brand from USA. They have very good reputation in DRAM products.
CORSAIR PSU product is just around 3 years. Their products are positioning at high quality and stability for mid-high end.

Previously, CORSAIR PSU has HX, TX and VX series. The highest one is 80Plius Silver certificate.
In months ago, they launched new AX, GS, and CX product series.
This review is most high end AX series, the 80Plus Gold level.
It belongs to Professional Series Gold. AX has 3 products, 750/850/1200W.
I use entry AX 750W to share this latest high end PSU.

First of all, let’s see the package. The box main symbols are spec and technical feature.
7 years warranty, 80Plus Gold certificate are 2 main features.
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Accessories
Product manual, cable ties, CORSAIR sticker, screws and power cord
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PSU body is packed by flannelette bag
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Professional Series Gold AX750W Body
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The shell is black matt baking for good quality.
Hybrid Silent Fan Control technology has Fanless mode, Quiet mode and Cooling mode.
When the PSU output below 20%, the fan is complete stationary and silent.
Quiet mode is working as PSU output between 20~50%.
The fan starts to work and the noise level is 16dBA.
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High quality cable collecting pack and modulized cables
12 X SATA
8 X 4 Pin
2 X Floppy
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1 X ATX 24 Pin
1 X EPS/ATX12V 8/4 Pin
4 X PCI-E 6+2 Pin
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The back design is cell heating holes.
Active PFC spec for 110~240VAC
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Product Spec
Model, CMPSU-750AX
Simplex +12V design. Total is 62A and max is 744W
cax750w10.jpg
 
Modulized cable connectors. It can be better if it’s with clearly indicate.
Even MB 24/8 Pin cable is also moduliozed. It’s very rare design.
I remember there is only X-SERIES 750W using this.
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Take a look inside.(PS：Please don’t do it by yourself, due to it will be out of warranty.)
The fan is SANYODENKI 9S1212F404. 12cm dual balls bearing with temperature controller.
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A bird’s eye view
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Internal heatsink is black
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The capacitors are solid and Japanese made to enhance AX750W stability and durability.
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Double faced PCB design
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I guess CORSAIR AX750W and my previous review, Seasonic X-SERIES 750W, should be from same design team.
Many designs and components are similar. However, after checking the detail, the PCB design is some different.
CORSAIR PCB and heatsink are black and heatsink is bigger.
Also PCB some layout is changed. AX750W could be X-SERIES 750W revised version.

I use MB GIGABYTE X58A-UD3R; due to X58 is the most high end Intel platform.
It supports On/Off Charge, USB 3.0/SATA3, Cloud OC and 2oz copper PCB.
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The platform is X58A-UD3R with Intel Core i7-950.
The main reason is LGA1366 is the most power consumption platform so far. It’s very suitable for PSU loading test.
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System Configuration
CPU: Intel Core i7-950
MB: GIGABYTE GA-X58A-UD3R
DRAM: CORSAIR DOMINATOR-GT CMG6GX3M3A2000C8
VGA: GIGABYTE GTX460 OC
HD: Intel X25-V 40GB RAID 0
POWER: CORSAIR Gold AX750W
Cooler: Mega Shadow Deluxe Edition
OS: Windows7 Ultimate 64bit
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The test below is under default setup and OC CPU to 4140MHz to compare PSU output status in middle and high power consumption modes.

Default Setup
CPU 133.2 X 24 => 3197.7MHz
DARM DDR3 1865.2 CL7 8-7-20 1T
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OCCT V3.1.0
POWER SUPPLY Mode
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Enter to OS desktop - 153~156W
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Run OCCT Power Supply Test Items
i7-950 default is 3.07GHz. 4 physical cores and 4 HT cores full load plus GTX460 - 392~418W。
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Power Angel shows this X58 default mode max power consumption is 418W
According to 80Plus website,
output 50% transfer efficiency is around 90.80%
After transferring, 110V 418W is around 380W real output.

OCCT Test Result
CPU Voltage Variation
Disable Intel C1E in default mode. CPU clock and voltage both rise to highest.
cax750wdvcore.png


3.3V
The highest is 3.34V and mostly it’s between 3.31~3.33V during test. The voltage wave is around 0.90%
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5V
Mostly it’s between 4.84~4.89V. The voltage wave is around 1.02%.
cax750wdvolt5.png


12V
The highest is 12.37V and the mostly is 12.24V. The voltage wave is 1.05%.
cax750wdvolt12.png


3V and 5V voltage wave is around 0.9~1.02%. It’s very good condition.
Even 12V is only 1.05%. You can see this PSU in high load condition is still working excellent.

Using More Accurate Meter
Idle
5V testing result is 5.03~5.05V which is higher than board meterage 4.89V.
cax750d5vidle.jpg


OCCT Full Speed
The voltage is 5.06V which is higher than idle condition.
cax750d5vfull.jpg


Idle
12V testing result is 12.18~12.19V which is some different with board meterage 12.37V
cax750d12vidle.jpg
 
OCCT Full Speed
The voltage is 12.17V which is lower than idle condition around 0.01~0.02V
cax750d12vfull.jpg


5V is rising to higher voltage in full speed condition.
12V only has 0.01~0.02V small wave. This meterage is much lower than mainboard measurement.

OC System Setup
CPU 180 X 23 => 4140MHz
DARM DDR3 1800 CL7 8-7-20 1T
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Enter to OS Desktop - 186~190W
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Run OCCT Power Supply Test Items
i7-950 OC to 4.14GHz, 4 physical cores and 4 HT cores full load plus GTX460 - 596~636W。
cax750ofull.jpg


Power Angel shows this X58 OC mode max power consumption is 636W
According to 80Plus website, there are only 20, 50 and 100% transfer efficiency.
I decide to use transfer efficiency at 100% and it’s about 88.11%
After transferring, 110V 636W is around 560W real output.

OCCT Test Result
CPU Voltage Variation
Disable Intel C1E in default mode. CPU clock and voltage both rise to highest.
cax750wovcore.png


3.3V
The highest is 3.33V and mostly it’s between 3.28~3.3V during test. The voltage wave is around 1.50%
cax750wovolt3.png


5V
Mostly it’s between 4.87~4.76V. The voltage wave is around 2.26%.
cax750wovolt5.png


12V
The highest is 12.3V and the mostly is between 12.18~12.24V. The voltage wave is 0.96%.
cax750wovolt12.png


3V and 5V voltage wave is around 1.5% and 2.26%.

Even 12V is only 1.05%. You can see this PSU in high load condition is still working excellent.

3V and 5V voltage wave is around 1.50 and 2.26%.
The wave range is higher than default mode. However, it’s still much lower than acceptable 5% tolerance.
12V is even lower. It’s just only 0.96%. You can see this PSU in 75% high load condition is still working excellent.

Using More Accurate Meter
Idle
5V testing result is 5.05V which is higher than board meterage 4.87V.
cax750o5vidle.jpg


OCCT Full Speed
The voltage is 5.06V which is lower than idle condition around 0.1V
cax750o5vfull.jpg
 
Idle
The voltage is 12.17~12.18V which is different with board meterage 12.3V
cax750o12vidle.jpg


OCCT Full Speed
The voltage is 12.14V which is lower than idle condition around 0.03~0.04V
cax750o12vfull.jpg


You can see no matter idle or OC, 5V is raising 0.1V
There is no 5V dropping 2.26% status in OCCT software.
12V wave is only 0.03~0.04V. Even though it’s bigger than default, it’s still only 0.33% wave.
These 2 factors are much lower than mainboard meterage.

CORSAIR Professional Series Gold AX750W Conclusion
Good
1.Professional Series new packing and accessories are very good quality
2.CORSAIR provides 7 years warranty
3.Modulized design for better flexibility. The inner capacitors are Japanese made and solid caps.
4.80Plus Gold Certificate and the energy efficiency is 90.80%
5.5V is no dropping in meter test and 12V is only falling 1%. The voltage wave is very small.
6.It supports Hybrid Silent Fan Control technology which fanless below 20% output.

Weak
1.Suggesting they can add 6 X PCI-E 6+2 Pin
2.80Plus Gold Certificate and good components make the price be too high

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Performance ★★★★★★★★★☆
Components ★★★★★★★★★★
Specification ★★★★★★★★★☆
Outlook ★★★★★★★★☆☆
C/P Value ★★★★★★★★☆☆

I used to review Seasonic X-SERIES 750W which is good components and performance Gold product.
You can see CORSAIR Professional Series Gold AX750W should be ODM by Seasonic.
Before, Seasonic ODM PSU has better components than own brand one.
AX750W inner layout is very different with X-SERIES 750W. I think it should be the revised upgrade version.

There are some special parts within my test.
First is the fanless mode in Idle condition. The PSU body temperature is also low.
During CPU/VGA full speed running, fan rpm is controlled by output rate. I don’t hear any obvious noise.
PSU body temperature is always below 40 degree C. It’s good control for noise and temperature.

CORSAIR AX750W price is around 170USD.
The key concerns of buying PSU are components, 80Plus Level, price, warranty and brand awareness.
AX750W is high end components level. I think 80Plus level doesn’t equal to components.
For the price, many non-modulized or lower components grade PSU price will be much lower.
I hope this review can be reference for the users who want to own a Gold Certificate and high end components PSU.
windwithme will introduce more Gold Certificate PSU in near future. Thanks. :)

This article is also in my blog WIND 3C. Any comments are always welcome :)
 
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