Corsair TX750W Review - Updated

paulktreg - 2008-09-12 12:46:53 in Power Supplies
Category: Power Supplies
Reviewed by: paulktreg   
Reviewed on: November 23, 2008
Price: $109.99

Introduction:

If right now you are thinking OCC has already reviewed the Corsair TX750W, then you would be correct. It was last looked at here in June 2008, so please go back and have a look at ccokeman's review and see how OCC once tested power supplies. Installing a power supply in a high end PC, software stressing the processor and graphics card to load the power supply and measuring the rail voltages is one way of testing. Some people might say this is a "real world" way of testing power supplies and many review sites are still doing it this way but, and I'm sure OCC won't mind me saying this, it can be done better.

Corsair has kindly supplied another TX750W power supply to OCC and this time round I will be loading the power supply up to or very near its maximum power and seeing how it performs. My testing methodology is by no means perfect, but it is the next logical step up and I'm confident my test regime will give accurate results from which I can reach a fair, accurate and valid conclusion.

"Enthuiasts looking for the optimal in price performance PSU technology will find the Corsair TX650/750W series of PSUs will meet even the most demanding of required specifications. The Corsair TX650/750W power supplies are engineered using advanced technology and components typically found with high performance power supplies. With design features such as a dedicated, single 12V rail, the TX series offers the maximum compatibility with the latest system components. Energy efficient circuitry capable of delivering 80% efficiency ratings across 20%, 50% and 100% load conditions make the TX family of PSUs ideal for the value/quality conscious enthusiasts. With a large 140mm (120mm on the TX650W) diameter temperature controlled fan that is ultra quiet, yet still more than sufficient to cool the internals of the system, reliability and stability are no longer worries for the gamer, overclocker or enthusiast and high end system builder. Each Corsair TX power supply is backed with an industry leading 5 year warranty and 24/7 on demand customer service."

Let's have a look at the Corsair TX750W and see how it performs.

Closer Look:

The Corsair TX750W packaging once again closely follows the layout used for the rest of its power supply range. This time around a black and orange theme is used. The lid shows the usual arty photograph of the power supply, a short five point list of the main features of the power supply in English, Spanish and French, the Corsair sailing ship logo with large TX750W logo and finally a five year warranty, 80 Plus and SLI ready icon. The underside of the box contains a wealth of information with various close up photographs of the power supply, a core features list, specification table, part number CMPSU-750TX and audible noise and efficiency graphs.

 

 

 

 

 

On the sides of the Corsair TX750W box there are photographs and quantities of all the connectors available along with a short paragraph or two, in three different languages, introducing the power supply and its main features

 

 

The sides of the box are identical and show the Corsair logo along with model number.

 

 

Lift the lid and the first thing you see is the user manual on top of the foam envelope that encases the power supply. The TX750W is non-modular and all the cables are neatly bound and tucked down the side of the power supply along with the power chord. The power supply is contained in a draw string black felt bag.

 

 

Photographs of the black felt covered power supply and neatly bound cables along with the enclosed accessories (power cord, user manual, power supply fixing screws, case badge and black cable ties).

 

 

The Corsair TX750W is well protected against transit damage and includes all necessary accessories for a successful installation. Let's have a look inside the felt bag.

 

Closer Look :

Outside of the bag the Corsair TX750W is finished in a slightly textured matte black paint finish which does have its advantages - no messy finger prints! Following on from the packaging the main theme colors are once again black and orange.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The rear side of the power supply showing the honeycombed air exhaust grill, IEC mains input and a rather small mains on/off switch, which are always difficult to find when reaching from the front of the computer. The front of the power supply doesn't have much to see. I wonder why can't the cables be sleeved all the way into the power supply, it looks much more professional that way.

 

 

Identical labels on both sides.

 

 

Specification label on the top and an external view of the large 140mm black seven bladed fan and black grill on the underside.

 

 

Very difficult, if not impossible, to get a neat picture of all the cables. All of the connectors types and quantities you are ever likely to need but cable management will need some work.

 

The large 140mm fan is a GP D14BH-12 (12VDC 0.7A) by Yate Loon Electronics. If you look closely, you will see that Corsair has fitted a clear plastic baffle covering almost fifty percent of the fan - more on this later. The internal layout is tidy with some room to spare. Enough room perhaps, and in the right place, for a modular version of the TX750W?

 

 

All the capacitors that I could identify are of Japanese manufacture and have the more acceptable 105°C temperature rating. The board is manufactured by CWT Co Ltd. All coils are sleeved and silicone rubber sealant, or some similar material, has been used at various points on the printed circuit board to help secure components and possibly help prevent component oscillation and that irritating buzzing noise that some power supplies emit as they age.

 

 

The Corsair TX750W has the look of a quality made power supply using quality components. Let's see how it performs.

 

Specification:

 

Ratings Table:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Corsair TX750W (CMPSU-750TX)
AC Input

100-240VAC     10A     50-60Hz

DC Output
+3V3
+5V
+12V
-12V
+5VSB
Maximum Load
30A
28A
60A
0.8A
3A
Maximum Combined Wattage
180W
720W
9.6W
15W
Total Power: 750W

 

System Protection:

 

No specific figures are given for system protection but the literature states that over current/voltage/power, under voltage and short circuit protection are all provided.

 

Safety & Agency Approvals:

 

UL,TUV, CE, FCC, CCC, CB & C-Tick.

 

Power Supply Weight:

 

Power Supply Weight
Manufacturer/Model
Weight
Corsair TX750W
2.5kg
5.5lbs

 

Power Supply Connectors:

 

Corsair TX750W Connectors
20+4 Pin Motherboard
Hard Wired
1
4+4 P4 ATX12V or EPS12V 8 Pin
Hard Wired
1
PCI-E 6+2 Pin
Hard Wired
4
4 Pin Molex
Hard Wired
8
SATA Power
Hard Wired
8
FDD
Hard Wired
2

 

Features:

 

Exactly as printed on the box.

 

 

...and a few additional features listed on the box.

 

Powerful

60A on a single +12V rail.

 

Energy Efficient

High efficiency design generates less heat.

 

Quiet and Cool

Thermally controlled 140mm fan.

 

Fully Compatible

Supports Intel/AMD, PCI-E 8 pin and SATA.

 

Supports Dual Graphics cards

Compatible with dual graphics card configurations.

 

Testing:

For more information on how we test our power supplies, please browse our testing methodology.

Electrical Safety:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Electrical Safety Test Class 1
Manufacturer/Model
Pass/Fail
Corsair TX750W
Pass

 

Short Circuit Protection:

I short circuited the 3V3, 5V0 and 12V rail in turn. The power supply did shut down, and once the short was removed and the unit switched off for at least one second, resumed normal operation. Although listed here at the beginning of the testing section, I tend to leave this test until the very end, in case it doesn't quite go to plan.

 

DC Output Voltage Load Regulation:

 

Testing @ 110VAC

 

 

110VAC - Total Load at 145W which is 19% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.34
3.16
10.55
3.135 – 3.465
Pass
+5V
5.11
4.82
24.63
4.75 – 5.25
Pass
+12V
12.15
7.76
94.28
11.4 – 12.6
Pass
-12V
12.09
0.36
4.35
10.8 – 13.2
Pass
+5VSB
5.11
2.16
11.04
4.75 – 5.25
Pass
Total Power Supply Loading
145W
 

 

110VAC - Total Load at 395W which is 53% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.33
8.10
26.97
3.135 – 3.465
Pass
+5V
5.11
9.61
49.12
4.75 – 5.25
Pass
+12V
12.17
24.95
303.64
11.4 – 12.6
Pass
-12V
12.24
0.37
4.53
10.8 – 13.2
Pass
+5VSB
5.10
2.16
11.02
4.75 – 5.25
Pass
Total Power Supply Loading
395W
 

 

110VAC - Total Load at 747W which is 100% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.33
12.55
41.79
3.135 – 3.465
Pass
+5V
5.11
13.88
70.93
4.75 – 5.25
Pass
+12V
12.20
50.69
618.42
11.4 – 12.6
Pass
-12V
12.45
0.38
4.73
10.8 – 13.2
Pass
+5VSB
5.09
2.16
10.99
4.75 – 5.25
Pass
Total Power Supply Loading
747W
 

 

Testing @ 230VAC

 

 

230VAC - Total Load at 145W which is 19% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.34
3.14
10.49
3.135 – 3.465
Pass
+5V
5.11
4.82
24.63
4.75 – 5.25
Pass
+12V
12.15
7.76
94.28
11.4 – 12.6
Pass
-12V
12.10
0.36
4.36
10.8 – 13.2
Pass
+5VSB
5.10
2.16
11.02
4.75 – 5.25
Pass
Total Power Supply Loading
145W
 

 

230VAC - Total Load at 395W which is 53% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.33
8.16
27.17
3.135 – 3.465
Pass
+5V
5.11
9.61
49.12
4.75 – 5.25
Pass
+12V
12.18
24.91
303.40
11.4 – 12.6
Pass
-12V
12.24
0.37
4.53
10.8 – 13.2
Pass
+5VSB
5..10
2.16
11.02
4.75 – 5.25
Pass
Total Power Supply Loading
395W
 

 

230AC - Total Load at 748W which is 100% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.33
12.70
42.29
3.135 – 3.465
Pass
+5V
5.11
14.11
72.10
4.75 – 5.25
Pass
+12V
12.18
50.77
618.37
11.4 – 12.6
Pass
-12V
12.46
0.38
4.73
10.8 – 13.2
Pass
+5VSB
5.09
2.16
10.99
4.75 – 5.25
Pass
Total Power Supply Loading
748W
 

 

The Corsair TX750W rails held up very well even under full load and easily maintained a level well within the limits laid down by the ATX12V specification.

 

Testing (Continued):

The efficiency and power factor levels for the TX750W are good and meet the requirements of the claimed 80 Plus certification. The 110VAC efficiency at 747W does actually work out at ([747/938]*100) 79.64% but I do tend to round up and allow for some margin of error. The claimed 0.99 power factor isn't maintained at 230VAC but, as is usually the case, at 110VAC the power factor never drops below 0.99. The main market for Corsair is probably North America so is the specification for this, and other manufacturers power supplies, slightly biased toward the lower 110VAC mains supply?

Efficiency and Power Factor:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Output & Efficiency at 110VAC
DC Load (W)
AC Load (W)
PF
Efficiency (%)
Pass/Fail
0
10
0.59
N/A
N/A
145
180
0.99
80
Pass
395
475
1.00
83
Pass
747
938
1.00
80
Pass

 

Output & Efficiency at 230VAC
DC Load (W)
AC Load (W)
PF
Efficiency (%)
Pass/Fail
0
11
0.31
N/A
N/A
145
177
0.91
82
Pass
395
462
0.96
85
Pass
748
893
0.98
84
Pass

 

 

AC Ripple On DC Outputs:

 

First, and once again, I apologize for the poor quality photographs. My USB oscilloscope has gone to the "Electrical Items Only Skip" in the sky. The photographs below are from my trusty old CRT oscilloscope. It carries a valid calibration certificate but the triggering and focus could be better which is why the tracing appears blurred, it just refused to lock onto the high frequency signal. However, it does illustrate the amplitude of the signal, which to be honest, is all that I am interested in. I made ripple measurements at 230VAC and 110VAC but they are very similar (slightly higher at 230VAC) and the photographs below show 230VAC ripple only.

 

AC Ripple On 3V3 Rail at 230VAC

 

(Amplitude: 10mV/div | Timebase: 20uS/div)

 

 

AC Ripple On 5V0 Rail at 230VAC

 

(Amplitude: 10mV/div | Timebase: 20uS/div)

 

 

AC Ripple On 12V Rail at 230VAC

 

(Amplitude: 20mV/div | Timebase: 20uS/div)

 

 

Corsair TX750W AC Ripple/Noise Measurements

DC Output
+3V3
+5V0
+12V1
+12V2
-12V0
+5VSB
Ripple (mV p-p)
50
40
110
110
50
40
Pass/Fail
Pass
Pass
Pass
Pass
Pass
Pass

 

The AC ripple/noise levels on the Corsair TX750W meet the requirements of the ATX12V specification, but as you can see in the above table, they are quite close to the allowable maximum levels (50mV maximum for the 3V3 and 5V0 rails & 120mV maximum  for the +12V rail). Don't forget that these measurements have been taken with the power supply fully loaded.

 

Testing(Continued):

Temperature, Noise Levels and Fan Speeds:

 

I am not going to give a pass or fail in this section, as the ATX12V V2.2 does not really have any references on which to base a decision.

Temperatures are purely for information only, as there are too many variables involved when installed in a case, which, by the way, it wasn't. Ambient temperature, processor cooling efficiency and case cooling fans all play their part on the temperature of the air entering the power supply, and consequently the temperature of the air leaving it. No valid conclusions can be made from this test.

 

 

 

 

 

 

 

 

 

 

 

 

 

DC Load (W)
Temp In (°C)
Temp Out (°C)
Δ Temp (°C)
Fan Speed (RPM)
0
N/A
N/A
N/A
1101
145
21.0
30.6
9.6
1100
395
20.2
36.7
16.5
1270
747
21.3
43.6
22.3
2016

 

Temperatures are comparable to other power supplies in the same class and I can't foresee any problems in that department. Fan noise, in my opinion, is quite reasonable until you fully load the TX750W, at which point the fan ramps up to 2016 RPM and becomes noticeably louder.

The Corsair TX750W is fitted with a clear plastic fan baffle that covers approximately fifty percent of the total fan area and I have to ask, is it really needed? The reason for its inclusion must be to improve cooling but I couldn't help but notice a quite powerful airstream leaving the fan in the area of the baffle. This isn't the first time I've seen the baffle fitted so just out of interest I removed it and ran the power supply at full load for over two hours and the only difference I observed was a reduction in fan noise, temperature difference was negligable. This is just an observation and I don't advise anybody attempting to remove or run the power supply without the baffle, the designers must have their reasons for its inclusion, even if I can't find it!

 

 

Conclusion:

Environmental Factors:

WEEE and RoHS compliance along with high efficiency and good power factor earn the TX750W a few points in this section. What is the point of the black felt draw string bag and is it really necessary? Foam packaging is once again used when alternatives are available. The user manual for the TX750W, in several different languages, contains forty pages that could be printed on recycled paper.

 

Price Per the Watt:

Power Supply Corsair TX750W at $109.99 = $0.15/Watt (November 2008)

 

If, like me, you are a regular visitor to the OCC forums you have probably noticed that the Corsair TX750W power supply gets more than its fair share of recommendations. Is this justified? I have tested this power supply just like any other that crosses my doorstep and the answer is a resounding yes.

Best bang for your buck is a term you will see quite regularly and it accurately sums up the Corsair TX750W. The DC voltage load regulation is excellent, measured results justify its 80 Plus certification and DC quality, although not the best I have seen, still meets the requirements of the ATX12V specification.

The single 12V rail design means load balancing isn't needed and makes installation a breeze for the less experienced system builders. It's non modular design does mean lots of cables that will require a little thought and careful cable routing at the installation stage to enable efficient case airflow and give a tidy appearance.

If you are in the market for a 750W power supply then I highly recommend the Corsair TX750W and even if you don't need all the power, it's still worth considering for your next build. The price, at the time of writing this article, makes the Corsair TX750W excellent value for money. The Corsair TX750W is Nvidia SLI certified for dual 8800GTX graphics cards and if you intend to start off with a single graphics card and upgrade to SLI or Crossfire sometime in the future, then consider using the TX750W, you won't regret it.

 

Pros:

 

Cons: