Corsair TX 750M Power Supply Review (80 Plus Gold)

1. Introduction2. Bundle & Cables3. External4. Internal5. Testing Methodology & Results6. Closing Thoughts7. View All Pages

Today we test a Corsair power supply from their new TX-M series comprising a semi modular design, tight voltage control and 80 Plus Gold efficiency levels. Corsair say they have placed a lot of effort into reducing coil whine and are offering a 7 year warranty with this specific range of units.

Available in 550W, 650W, 750W and 850W models, the Corsair TX-M series incorporate 100% Japanese 105c Capacitors and rifled bearing fans which offer long life and low noise characteristics. Older TX M models were Bronze certified – the new units are enhanced to Gold efficiency standards.

Specification:
– Model: TX750M
– Power: 750 Watts
– 80 Plus: Gold
– MTBF: 100,000 hours
– Fan bearing technology: Riffle
– Fan size (mm): 120
– Modular: Semi
– Safety: Over-voltage protection, under-voltage protection, short circuit protection, over power protection, and over temperature protection
– Safety and Agency Approvals: FCC, ICES, CE, UL, cUL, RCM, TÜV, CB, CCC, BSMI, EAC, RoHS, WEEE, KC
– Compatibility: ATX12V v2.4 + EPS 2.92 & backward compatible with ATX12V 2.2, 2.31
– Product Dimensions (mm): 150 x 140 x 86
– Weight: 1.7
– Warranty: 7 Years

Official Pricing information from Corsair:
TX550M: $79.99 USD MSRP
TX650M: $89.99 USD MSRP
TX750M: $109.99 USD MSRP
TX850M: $129.99 USD MSRP

Review photography handled in house at KitGuru with a Leica S series medium format camera and S series prime lens. Please do not use any of the images within this review without express permission.

The Corsair TX750M arrives in a large box accented with yellow panels. A high resolution image of the power supply is shown on the front of the box along with some specifications such as the 80 Plus Gold Certification and 7 year warranty.

The rear of the box highlights the efficiency levels and fan noise levels. Our box was very much the worse for wear when it arrived with us from Asia. Clearly Messi and Ronaldo decided to have a kick about before UPS moved it through Europe. It just goes to show how important the box protection can be – the power supply was fortunately unscathed inside.

Inside the box we have a user manual, regional specific power cable, screws, warranty information and the modular cables inside a clear protective wrapping.

Above (left) the hard wired ATX (sleeved) and CPU cable. Above (right) – the modular cables which are all flat ribbon style for ease of routing.

Above, the cable breakdown chart of the full range of new TX-M Gold rated power supplies.

The Corsair TX 750M is a basic, but effectively designed power supply – in a simple black and white colour scheme. The paintwork is nicely finished and is fairly resistant against scratching.

The large Corsair fan is hidden behind a black grill with the company logo on full show in the centre.

One side of the power supply is home to the modular bay which is pretty much bulletproof to follow. Not only is it clearly labelled, the PCIe and CPU sockets are 4+4 pin, whereas all the peripheral ports are 3+3 pin. Even the most ham fisted system builders would have a hard time messing this one up.

Corsair TX 750M Power Supply
DC Output	+3.3V	+5V	+12V	-12V	+5Vsb
Max Output	25A	25A	62A	0.8A	3A
Total Power	130W		744W	9.6W	15W
	750W

This supply can deliver 62A on the +12V rail meaning there is plenty of power on hand for a powerful SLI and Crossfire configuration. It can deliver over 93% of its total available power over the +12V rail alone.

Corsair are using their NR120L fan in this unit which is made in China and rated 12V DC 0.22A. Corsair claim this is a custom fan created for high static pressure and the blades are designed to create static pressure with balancing throughout to reduce resonance at higher speeds.

If you are paying attention you can see there is a clear piece of plastic over part of the fan – this is to specifically direct the air flow over key parts of the unit underneath.

Rifle bearing fans are made for long life and quieter operation when compared to a standard ball bearing fan.

Below - a High Resolution Gallery of the internal layout of the Corsair TX 750M Power Supply

The internal build is relatively clean throughout although we noticed there was quite a lot of white fast setting adhesive used throughout, likely to help keep components from vibrating. Soldering on the PCB is very clean across the board.

Corsair are using Japanese capacitors on both primary and secondary stages, which is always good to see. The two primary caps are high grade Nippon Chemi Con, 105c rated, from their excellent KMR series. These individual caps are rated 420v 330uF, for a total of 660uF output. This is a reasonably healthy output for a 750 watt power supply.

A small daughtercard handles the +3.3V and +5V DC to DC and beside this card are the secondary output capacitors. The PFC IC is the Champion CM6500. The LLC and SR IC is the Champion CM6910 and the DC to DC PWM IC Is the Anpec APW7159.

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	0.95	3.35	0.90	5.03	5.18	12.05	0.50	5.01	0.20	-12.04
150W	1.67	3.35	1.68	5.03	10.73	12.05	1.00	5.01	0.20	-12.04
375W	3.00	3.34	3.08	5.03	28.18	12.04	1.50	5.00	0.30	-12.05
565W	4.00	3.34	4.05	5.02	42.90	12.02	2.00	5.00	0.30	-12.04
750W	4.91	3.33	5.08	5.01	57.35	11.98	2.50	5.00	0.50	-12.05

Load regulation is excellent, holding tight and well within 1.5%.

Corsair TX 750M	Maximum Load
	851W

We managed to reach around 851W before the unit would shut down gracefully, after the protection kicked in. This is a full 100 watts more than the unit is officially rated. A good result.

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	3.35	1.0	5.00	60.0	12.01	0.2	-12.03	0.50	5.00
154W	15.0	3.32	15.0	5.03	2.0	12.07	0.2	-12.05	0.50	5.00

The unit passes our Cross Load testing with flying colours. When hit with 60 Amps the unit holds steady at 12.01 Volts.

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	5	10	10	5
150W	10	10	15	5
375W	10	15	20	10
565W	10	15	25	10
750W	10	15	30	10

Ripple results are very strong indeed with the +3.3V and +5V rails peaking at 10mV and 15mV respectively. The +12V rail peaks at 30mV when under full load. Excellent results.

Efficiency (%)
75W	87.55
150W	91.54
375W	92.83
565W	91.23
750W	90.56

Power efficiency rates as very good indeed, hitting a peak close to 93% at 50% load. At full load it drops to 90.5%, another stellar result.

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	33.4
750W	34.9

The large fan in the TX 750M spins very slowly at low to moderate demand and can barely be heard, even with an ear close to the exhaust panel of the chassis itself. At higher load demands the fan spins up a little to around 1,300 rpm, which rated close to 35dBa in our tests. Its audible, but never really intrusive. These are very good results indeed.

Temperature (c)
	Intake	Exhaust
75W	36	39
150W	38	41
375W	39	45
565W	45	53
750W	47	59

The high levels of efficiency of this unit help reduce expelled heat. At full load we measured a +12c variable.

Maximum load	Efficiency
851W	89.74

For those interested, we measured efficiency when stressing the unit to breaking point. 89.7 percent efficiency at 851W … hardly practical, but interesting regardless.

The Corsair TX 750M is a very capable power supply which ticks a lot of boxes. It is a subtle looking unit which will fit well into any system build- thanks to the monochrome colour scheme. The quality of paintwork is high and the overall finishing is certainly above average for this sector.

Older TX-M units were Bronze rated, but Corsair have moved with the times and efficiency has been improved now to 80 Plus Gold levels. Our testing earlier in this article shows that the TX 750M Gold passed the 92% efficiency point at 50% percent load, hitting almost 93% in fact.

Technically, the TX 750M is a solid design. Ripple suppression rates as excellent, with all rails falling well within industry rated tolerance specifications and it passed the cross load test with flying colours. The build quality is generally very high inside and its always reassuring to see that 105c Japanese Capacitors are used throughout – especially for long term stability and reliability.

I actually hooked this power supply into a system I was testing, comprising two overclocked GTX 1080's in SLI, a watercooled, overclocked Intel Core i7 7700k and 32GB of DDR4 memory with multiple SSD's and HDD's. The system was rock solid across two days of real world testing and gaming and noise levels were never intrusive.

The only negative is that while Corsair list the official price of the TX 750M at $109.95 USD – in the United Kingdom the conversion rate is close to 1:1. You can buy it from Overclockers UK for £102.95 HERE. It is still pretty good value, but we do wish the UK prices would drop a little more, to sweeten the deal for us Brits.

Pros:

• Good build quality.
• low noise levels.
• ripple suppression.
• modular.
• efficiency is excellent.
• high grade cables.
• we heard no coil whine throughout testing.

Cons:

• UK pricing is a little high due to ‘Brexit' related nonsense.
• not pure modular.
• A lot of high grade competition around the £100 price point.

KitGuru says: The Corsair TX 750M is a very strong power supply and technically it delivers high quality power for demanding enthusiast system builds. It delivered around 850 watts in our testing before shutting down.

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