Silver Spec but Gold Strength, Power Saving PSU-CORSAIR HX750W Review

[windwithme]

Past few years, power supply products had big change.
Users can see more and more power supply brands in the market and spec is going higher and higher.
Few years ago, the manufacturers started to promote APFC and after then the high end power supply uses modulized design.
These two years, power saving becomes the power supply new spec.
80 Plus is the most popular one to count power efficiency of power supply.

CORSAIR is long history memory brand. His DRAM product has very good reputation in the market.
Even though CORSAIR just enters power supply market for few years, its products are good quality and stability.
COASAIR divides his power supply into 3 series.
HX series is the highest. It’s in modulized design. High quality also means high performance.
TX series has non modulized design, bigger watt and fair price.
VX series watt is smaller than TX. It’s suitable for users who have budget concern.

Last year you could see many CORSAIR power supply discussion and most strings are HX750W.
Recently, CORSAIR announced HX850W, but this review is still HX750W.
750W in watt combination and market price will be more acceptable for users.

Let’s look at the package first. It’s a bigger paper box.
Currently, most power supply provides 3~5 years warranty. HX750W has 7 year warranty.
It shows COSAIR’s confidence with their quality system.
HX750w also passed 80 Plus Silver certificate. Now the most common spec is Bronze certificate.


Accessories
High quality cables pack, multi lingual manual, cable ties, screws and power cables.


Modulized cables
4 X PCI-E 6+2 Pin
12 X SATA
8 X 4 Pin
2 X Floppy


Power supply packed by flannelette bag


CMPSU-750HX body




Cables extended from power supply
1 X ATX 24/20 Pin
1 X EPS/ATX12V 8/4 Pin


Back side deign is common cellular holes.
Active PFC in 110~240V


Modulized cable connectors
If they have some instruction stickers, that will be easier for users to understand clearly.


12 X 12 cm silent fan. The rotation rate is controlled by watt utilization.
Noise level, below 525W is 25dBA and 525~750W is 26~34dBA

[windwithme]

HX750W product spec
+12V only 1 loop and total is 62A. The max is 744W.


The test configuration is GIGABYTE P55A-UD6, the very high end spec in LGA 1156 products.
In the beginning, I planned to use LGA 1336 with Gulftown CPU to do the power consumption test.
However, base on my recent experience, when OC LGA 1156 to full speed, the 12V consumption is extremely high.


UD6 has USB 3.0 and SATA3, latest MB spec.



Configuration
CPU: Intel Core i7-870
MB: GIGABYTE P55A-UD6
DRAM: CORSAIR DOMINATOR-GT CMG4GX3M2A2000C8
VGA: GIGABYTE GTX260 OC SLI
HD: Seagate Barracuda XT 2TB
POWER: CORSAIR HX750W
Cooler: Tuniq Tower 120 Extreme
OS: Windows7 Ultimate 64bit


OS system set up
CPU 200 X 20 => 4000.6Mhz
DARM DDR3 2000 CL8 8-8-24 1T


OCCT V3.1.0
POWER SUPPLY mode, Shader Complexity 8


Above spec is the configuration for this review. It shows the power consumption status during test.
I use Power Angle measure number to the reference.

Enter to OS desktop - 230~231W


Running power supply test item in OCCT
i7-870 OC 4GHz, quad physical cores and quad HT virtual cores run in full speed plus GTX260 SLI 2WAY and GTX260 PhysX - 707~730W


Power Angle measure data is only for reference.
It only measures the approximate power consumption value. It’s not very accurate.
Even I didn’t use 3WAY SLI to reach the max 3D performance by full system load.
However, install one more GTX260 for PhysX also can increase some power consumption. It’s also some help for high loading test.

OCCT test result
CPU voltage variation
Standby is around 1.36V and full speed is always stay at 1.38V
CPU voltage vibration range is related to MB voltage quality.


3.3V
Max is 3.34V and it’s between 3.3~3.31V during test, about 1.20% range.

[windwithme]

5V
It’s between 5.05~5.08V, about 0.59% range.


12V
It’s between 12.42~12.55V, about 1.04% range.


HX750W 3V and 5V voltage vibration range is very low.
It’s really impressive.
You have to pay attention to that 12V consumption is much higher as OC LGA 1156 to 4GHz.
12V voltage drop is only 1.04%. HX750W is the best in my past experience in using power supply.

The whole platform full speed loading is over 700W.
HX750W body temperature is still low, around 40 degree C by hand-touch feeling.
Also, power supply back temperature is around 55 degree C. It’s acceptable range.
12cm fan speed acoustic is hard to hear. It’s rare performance for such high power consumption as HX750W.


The last part is using accurate power meter to measure.
Standby
5V measurement is 5.14V. It’s a little higher than MB value, 5.08V.


OCCT full speed
Voltage range is between 5.14~5.15V. Voltage rise 0.01V comparing to standby.


Standby
12V measurement is 12.12V It’s a little lower than MB value, 12.55V.


OCCT full speed
Voltage range is between 12.12~12.13V. Voltage rise 0.01V comparing to standby


As using meter, 5V and 12V are very still during standby and full speed.
Even the voltage change is only 0.01V. According to this measurement result, HX750W voltage stabilization is very high level.
Especially the 12V vibration range, very few power supplies can be as stay still as HX750W.


CORSAIR HX750W Conclusion
Good
1.CORSAIR package and accessories are good quality and also provides 7 years warranty.
2.Modulized design and 100% Japanese solid capacitors usage.
3.Passed 80PLUS Silver certificate and transfer efficiency is 90.02%
4. Temperature-controlled fan is very silent in normal usage. Even it’s hard to hear noise in full load condition.
5.Voltage vibration range is very low in high load. Especially the 12V is really impressive.

Weak
1.4 X PCI-E 6+2 Pin connectors are too less.
2.Matte paint outlook is easy to be scratched.



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

Someone think why I don’t use professional equipments to test power supply.
Maybe instrument test make readers feel more professional and credibility.
However, I think many brands power supply have made many test before selling.
If I use the same configuration as users real usage and test it in full load condition, it will be close to reality.
I used to suffer that a power supply passed professional instrument test, but has stability issue as installing to computer.

There is one more mystical thing. CORSAIR HX750W package shows 80 Plus Silver Certificate.
When I check in 80 Plus website, HX750W is Gold certificate and the power transfer efficiency is 90.02%.
CORSAIR designed it by Silver level, but some items have achieved Gold level.
It caused HX750W got Gold in 80 Plus, but still advertise it as Silver certificate.
This way is different as some brands only care about 80 Plus certificate but not product design and components.

CORSAIR HX750W owns high quality and high performance. Also, its package and components are good as well.
Plus above Silver level power efficiency, even though it’s 750W, but the power consumption is not much higher than low watt PSU during usage.
CORSAIR also provides 7 years warranty. You can see the vendor is very high confident with HX750W quality.
The CORSAIR HX750W price is around 150 USD.
But for middle high power supply, I think CORSAIR HX750W is still a very good C/P value product.
It’s in your must buy list if you are looking for same segment PSU. :)

[Zero82z]

Originally Posted by windwithme

Someone think why I don’t use professional equipments to test power supply.
Maybe instrument test make readers feel more professional and credibility.
However, I think many brands power supply have made many test before selling.
If I use the same configuration as users real usage and test it in full load condition, it will be close to reality.
I used to suffer that a power supply passed professional instrument test, but has stability issue as installing to computer.

The reason for testing with proper equipment is to ensure that the claims of the manufacturer or brand are accurate. Many PSUs are advertised with specifications that are beyond the PSU's true abilities. Your justification may be somewhat true when dealing with quality PSUs, but with many other units it is simply not the case.

I also have to take issue with your use of OCCT for voltage measurements. You already have a multimeter, so there is no point in checking voltages with OCCT since that already gives you more accurate measurements. If your intention is to use it to measure ripple, then you can just eliminate that right away since the sampling rate of the motherboard's sensor chip is nowhere near fast enough to actually capture any ripple. You would need to use an oscilloscope to perform those measurements.