Corsair 750W Enthusiast Series Modular PSU Review (TX750M)

1. Introduction2. Corsair TX750M (Bundle & Cables)3. Corsair TX750M (External)4. Corsair TX750M (Internal)5. Corsair TX750M (Super High Res Gallery)6. Testing Methodology and Results7. Closing Thoughts8. View All Pages

The technology industry has been very competitive now for a number of years, often forcing companies to diversify their range. Corsair, highly respected for their memory products expanded into other sectors, such as high end cooling, speakers and USB peripherals. Also, they have experienced great success in the power supply sector and today we are looking at their latest TX750M – a modular power supply with 80 Plus Bronze Certification.

The Corsair Enthusiast Series Modular 750W slots into the range, just under the 850W flagship. This is a single rail power supply which can deliver 62A on the +12 rail. It ships with four 6+2 pin PCI e cables and is supported with a reassuring 5 year warranty.

Corsair are also utilising an ‘ultra quiet' 140mm double ball bearing fan which is PWM controlled to keep noise levels as low as possible.

Technical Specifications

• A dedicated single +12V rail offers simple configuration and maximum compatibility with the latest graphics cards and other components
• An ultra-quiet, 140mm double ball-bearing fan delivers excellent airflow with exceptionally low noise levels by varying fan speed in response to temperature
• Complies with the European Union ErP Directive (2009/125/EC) so the power consumption of the whole system, in either standby or off mode, can be less than 1W when used with a properly configured, ErP-compliant motherboard
• 80 PLUS Bronze certified, delivering up to 85% energy efficiency under real-world load conditions
• Active Power Factor Correction (PFC) with PF value of 0.99
• Universal AC input from 90~264V
• Over-voltage, under-voltage, over-current, and short circuit protection provide maximum safety for your critical system components
• High-quality capacitors provide uncompromised performance and reliability
• A five year warranty and lifetime access to Corsair's legendary technical support and customer service

Corsair packaging really is a statement on how it should be done. A beautiful high resolution monochrome, artistic image with the name of the product bottom right.

The power supply is protected between two thick pieces of foam, with some literature and warranty information on top.

Corsair bundle a region specific power cable, mounting screws, some molex adapter cables and cable tidies for the final system build. The power supply is shipped protected inside a soft black felt bag.

The image above left, shows the cables that are hardwired to the main unit. Above right are four modular cables which can be added or removed, as needed.

The TX750M is supplied with plenty of cables, including 4x 6+2 pin PCI E connectors for demanding Crossfire and SLI system builds. The cables are all quality sleeved and extra long length.

The power supply follows the traditional Corsair design, plain black/dark grey, with a colour coded label on the side. We like the quality of the matt paintwork as it doesn't mark easily, holding a pristine finish.

The large 140mm fan is visible from the top, with the Corsair badge centerstage in the middle.

The modular cable connectors are colour coded to keep the installation phase as straightforward as possible. There are only four on this particular design as detailed on the previous page.

There is a power plug and power switch on the other side, next to a vented section for airflow. The supply is sealed with tiny screws requiring a special driver. Opening the unit invalidates the 5 year warranty, so we don't recommend you attempt it.

62A available to the 12V+ output, for 744W of the total output.

Corsair are using a Yate Loon D14BH-12 fan which is a 12 volt design – the fan can spin up to 2,800 rpm generating a whopping airflow of 140 cfm. The maximum noise is rated to 48.5 dBa, but Corsair should have the product configured to spin much slower.

Corsair are using a Channel Well Technology (CWT) design for this particular unit – the same company who also produced the first TX power supplies. Corsair have worked with SeaSonic in the past, and both of these manufacturers are capable of great designs. The transient filtering stage starts at the AC receptacle and consists of two Y and a single X cap. It is a capable configuration.

The main capacitor is from Panasonic and is rated at 105c, 470uF, 400V. We noticed a SBL1040CTP being used for the 5VSB output with a Nippon Chemi Con capacitor. All capacitors on the secondary side are actually Nippon Chemi Con. On the modular PCB, next to the VRM's, polymer caps are used. The cabling is fully sleeved inside the chassis and tied tightly to ensure fraying is not a long term concern.

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	1.24	3.37	1.17	5.06	4.92	12.14	0.50	5.04	0.20	-12.05
150W	2.19	3.35	2.81	5.04	10.03	12.09	1.00	5.03	0.30	-12.05
375W	6.13	3.30	6.02	5.02	26.12	12.06	1.50	5.01	0.50	-12.06
565W	10.32	3.28	10.83	4.99	38.32	12.04	2.00	4.98	0.60	-12.07
750W	10.71	3.27	13.82	4.97	53.56	11.97	3.00	4.95	0.80	-12.08

The Corsair power supply has strong load regulation, with only minor deviation. These are great results and the rails remained firmly within +/-3% of the nominal voltage.

Corsair TX750M	Maximum Load
	824W

We managed to reach around 824W before the unit would shut down gracefully, after the protection kicked in.

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	3.34	1.0	5.03	60.0	11.96	0.2	-12.05	0.50	5.03
154W	15.0	3.28	15.0	4.95	2.0	12.11	0.2	-12.05	0.50	4.99

Fluctuation is held safely within the rated parameters, even when we load the 12V line with 60A.

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	10	10
150W	10	10	15	10
375W	15	15	20	15
565W	15	15	30	15
750W	20	20	35	15

Ripple results are very good on all the rails, holding well within the tolerance guidelines. The 12V+ output is particularly impressive, peaking at 35 mV.

Efficiency (%)
75W	84.21
150W	87.87
375W	88.69
565W	87.21
750W	85.89

The Corsair is very efficient for an 80 Plus Bronze rated unit, peaking at just under 89 percent efficency at 50 percent 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 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	27.9
150W	27.9
375W	28.2
565W	32.9
750W	35.8

This power supply is extremely quiet, registering at the lowest limits of our equipment, until loaded to around 50% of the total output. It becomes audible in the last 20% of the maximum power figure.

Temperature (c)
	Intake	Exhaust
75W	36	39
150W	38	41
375W	39	45
565W	43	49
750W	44	51

Exhaust temperatures are impressive, reaching a maximum delta of 7c above intake at full load.

Maximum load	Efficiency
824W	84.2

For those interested, we measured efficiency when stressing the unit to breaking point. 84.2 percent efficiency at 824W … hardly practical, but interesting regardless.

As with all the Corsair power supplies we have tested to date, the TX750M delivers some fantastic all round results, highlighting a very capable, balanced design.

The new modular release will appeal to a wider audience, especially those with windowed panels, who want to build an attractive, cleanly routed system. That said, Corsair could have improved this aspect further by removing a few more of the hardwired (native) cables and making them modular.

Internally, the Channel Well Technology design is excellent with no noticeable or glaring issues. Load regulation is solid, and the noise suppression results are as good as we have seen from a power supply in this sector. The design handled our stressful cross loading tests with relative ease.

The choice of large, (almost) silent fan also ensures that the TX750M be a suitable choice for a performance oriented media system, as the fan doesn't really spin up until around 50% of the maximum rated load (375 watts). Only in the last 20% of total power output did we notice any fan related noise emission, so the potential audience for this particular design is huge.

As with any purchase in this sector, much of the buying decision will be based on the price.

In the UK Dabs are stocking this power supply for only £90 inc vat.

Pros:

• Efficient.
• looks great.
• bundle is excellent.
• passed all load tests.
• noise suppression (mV) is class leading.
• quiet.
• price point is competitive.

Cons:

• more modular cables would have been better.

Kitguru says: A great release from Corsair, very well balanced in all areas with no discernible problems.

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