Antec Signature 850W Review

paulktreg - 2008-09-09 11:59:06 in Power Supplies
Category: Power Supplies
Reviewed by: paulktreg   
Reviewed on: September 18, 2008
Price: $229.00

Introduction:

More and more consumer electronics manufacturers are striving ever harder to improve the energy efficiency of their products in a bid to convince us that their product is the one to buy. This is, in my opinion, a very welcome trend and nowhere is it more evident than in the personal computer power supply market. Energy prices are rising all the time and I don't think the average PC user out there really appreciates, or even gives too much thought, to how much their high performance gaming rig is costing to run (for example a high end PC @ 400W = 0.4kWh at $0.10/KWh; for four hours/day = $58.40/year and 24/7 = $350.40/year). Individually, this doesn't seem like much, but if you are running several rigs the costs soon mount up.  If every PC user ensured they had an energy efficient power supply installed, the combined energy savings would be significant. The 80 Plus program has helped standardise measurement of power supply efficiency and encourage sales of more efficient units. Let's have a look at the Antec Signature 850W with a claimed 80 Plus Bronze certification. (82%-85%-82% efficiency at 20%-50%-100% load).

Antec, founded in 1986, is a leading supplier of computer accessories for gaming, PC upgrades and the do-it-yourself market. Antec's offerings include a large range of PC cases, power supplies and cooling solutions. The semi-modular Signature 850W, also available as a 650W variant, is Antec's highest powered premium line power supply.

 

Closer Look:

The first thing I noticed about the packaging of the Antec Signature is the card sleeve covering the "shoe box" type packaging. It looks fantastic but I feel it lacks the basic information provided by other manufacturers. The sleeve is fixed to the packaging by two clear plastic stickers and is not something you would remove before purchase. You get the Signature logo on the front panel and a specifications label on the underside, but no features. How is the buyer supposed to know what the power supply offers? This power supply is primarily aimed at the enthusiast's market and perhaps Antec can be forgiven for this omission because most people, me included, would do some research before spending this much money.

 

 

 

Removal of the sleeve reveals the plain black and yellow themed box with the Antec logo on the black lid. The bottom of the box is the same as the lid so that a thin yellow stripe is visible all around. Inside, the first thing you see is a windowed black card insert that keeps the user manual in place.

 

 

 

Remove the back insert, user manual and test certificate, more on this later, and the power supply is neatly stored in a foam compartment which can be easily lifted out  to reveal the main chord and modular cables neatly packed in plastic bags.

 

 

 

The power supply is protected with a simple cellophane wrap and the cables neatly held together with ties. You will see from the photographs that this power supply is not fully modular and comes complete with enough basic connectors to complete the build process without the addition of the modular connectors. Some power supplies are fully modular but I have to ask, why? All computers require the motherboard 20/24 pin and an auxillary power connector or two, so why make these modular? The full set of hard wired connectors consists of the 20/24 pin motherboard connector, one 4-pin and one 8-pin auxillary power connector, three 4-pin Molex + FDD power connectors, three SATA power connectors and two 6/8-pin PCI-E connectors. If you want to install extra drives or even two Geforce 9800 GX2 in SLI (for which this power supply is Nvidia certified), then the modular cables will be needed. I feel this is a sensible approach, why introduce extra plugs and sockets when they're not needed?

 

 

Included with the Antec Signature 850W is a test report telling us that 80 Plus, Full Load Line Regulation, Short Circuit, Over Voltage and Over Current tests have all been successful and stamped pass by T. Xiang. Why not save him, or her, the effort of "pass stamping" and get it printed as they are hardly going to release one with a big red FAILED!

 

 

The Antec Signature 850W is very well packaged and should easily withstand the ordeal of going through any of the world's postal systems. Next we will have a closer look at the power supply, inside and out.

 

Closer Look:

The power supply comes in a basic matte black paint finish with an Antec name plate recessed into the top cover. The back panel sports an honeycombe grill for the cooling fan, IEC mains input socket and an on/off switch.

 

 

 

 

 

 

 

 

 

 

Note the addition of the warranty sticker over the top panel case screw - break this and your warranty is invalid. Breaking warranty stickers is something I live for but please, do not do this at home unless you know what you are doing. There are some very dangerous voltages lurking around in power supply cases and there really is no need to open them. The often seen "no user serviceable parts inside" is usually the case, even fuses these days are often obscure types, difficult to obtain and sometimes soldered but there really is no excuse for a fuse to blow in high quality power supplies like the Signature as the protection circuitry should cut in and prevent this from happening. If a fuse has blown it's usually a sign that there is a serious problem. The photo below on the right shows the air intake grill, four connectors for the modular cables and the exit port for the hard wired cables.

 

 

 

You get the specification label on one side and that's it as far as labels and logos. The Antec Signature 850W comes with a good basic selection of hard wired cables which are listed later. You are given a total of 20 inches of cable up to the first connector, with multi-connector cables having a six inch spacing after that. I particularly liked the retention method used for the cable sleeve; instead of commonly used heat shrink sleeving, which often works loose, Antec has used hard moulded plastic collars that look like they will last forever.

 

 

 

Lift the lid and the first thing you see is an insulator sheet to prevent the top printed circuit board from shorting on the case. This has been removed for the photograph on the left. This power supply is unusual in that it contains two printed circuit boards. The photographs below show the top board inverted and after the removal of a few screws and two connectors, tipped over to reveal the component side. For your information the two main smoothing capacitors are by Rubycon, the rest are a mixture of Nichicon and Chemi-con. The top board takes the raw mains voltage for rectification, smoothing and processing via the switched mode circuitry before passing this processed voltage down to the bottom board for final regulation.

 

 

 

The Antec Signature, unlike most power supplies, uses DC to DC regulator modules to supply the 3V3 and 5V0 rails. These are located in the area of the copper plate seen in the photograph below. The white component on the heatsink is the temperature sensor that governs fan speed. The 80mm fan is a Nidec Beta SL 12V DC (Model D08A-12PS3) which is claimed to run far quieter due to its pulse width modulated (PWM) supply.

 

 

 

The final photograph in this section shows the rear of the modular cable connection sockets.

 

 

All in all the Antec Signature 850W is, externally and internally, a very well made unit. Let's see how it performs.

Specification:

 

 

 

 

 

 

 

 

 

Input
100VAC-240VAC | 13A-6.5A | 47Hz – 63Hz
Voltage
3V3
5V0
12V1
12V2
12V3
12V4
-12V
5VSB
Maximum Load
25A
25A
22A
22A
25A
25A
0.5A
3A
Minimum Load
0A
0A
0A
0A
0A
0A
0A
0A
Regulation
±3%
±3%
±3%
±3%
±3%
±3%
±6%
±3%
Ripple & Noise
50
50
120
120
120
120
120
50
Combined Max
160W
780W
N/A
N/A
Total Power
850W Continuous @ 50°C

 

Note: The maximum output power given in the manual is 850W. The specification label on the side of the power supply also states a 829W maximum for combined 3V3, 5V and the four 12V rails. I have a fixed 15.5W load on the 5VSB and -12V rails which effectively gives me a maximum of 844.5W for the Antec Signature. This is the figure I will base my tests on.

 

System Protection

There are no specific figures given for the protection circuitry. The following information is given in the user manual:

"A variety of industrial-grade safety circuitry will help protect your computer: OVP (Over Voltage Protection), SCP (Short Circuit Protection) and OCP (Over Current Protection). Sometimes the PSU will latch into a protected state. This means that you will need to clear the fault and turn the power off to the PSU before it will function again. There are no user replaceable fuses in your Signature series PSU."

If you refer to the test certificate on the first page we are given written "proof" that all these safety features have been tested and passed by T. Xiong before the PSU is released.

 

Power Supply Weight
Manufacturer/Model
Weight

Antec Signature 850W

2.78kg
6.14lbs

 

 

Antec Signature 850W Connectors
20+4 Pin Motherboard
Hard Wired
1
PCI-E 6+2 Pin
Hard Wired
2
EPS12V 8 Pin
Hard Wired
1
P4-12V 4 Pin
Hard Wired
1
Molex 4 Pin
Hard Wired
3
SATA Power
Hard Wired
3
FDD 4 Pin Power
Hard Wired
1
PCI-E 6 Pin
Modular
2
Molex 4 Pin
Modular
6
SATA Power
Modular
6

 

 

Features:

Unlike the other power supplies I have tested I cannot find a definitive list of features in the accompanying literature. The list of features below is taken from the Antec website.

 

Testing:

For more information on our testing system, please browse our testing methodology.

Electrical Safety:

 

 

 

 

 

 

 

Electrical Safety Test Class 1
Manufacturer/Model
Pass/Fail
Antec Signature 850W
Pass

 

Short Circuit Protection:

I short circuited the 3V3, 5V0 and all four 12V lines 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

I have again tested at 240VAC and 110VAC. This will provide extra information for those of you using the lower mains input voltage. Before you say it should be 120VAC, all I can say at this stage is I haven't been able to lay my hands on a Variac. The 110VAC test has been performed using a power tool isolation transformer commonly found on building sites up and down the country. The difference between the results at 110VAC and 120VAC will be negligible, as will the frequency difference of 50 or 60Hz. I have tried to space my load tests evenly over the full range, result tables below, and I have included the information in graphical form for the first time. The output voltages for the 12V1,12V2, 12V3 and 12V4 lines are very close, and I have plotted an average of the four voltages for the graphs.

Testing @ 110VAC:

 

 

110VAC - Total Load at 172W which is 20% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.31
3.11
10.29
3.135 – 3.465
Pass
+5V0
5.03
4.66
23.44
4.75 – 5.25
Pass
+12V0(1)
12.09
2.56
30.95
11.4 – 12.6
Pass
+12V0(2)
12.09
2.56
30.95
11.4 – 12.6
Pass
+12V0(3)
12.08
2.55
30.80
11.4 – 12.6
Pass
+12V0(4)
12.07
2.54
30.66
11.4 – 12.6
Pass
-12V0
11.97
0.36
4.31
10.8 – 13.2
Pass
+5VSB
4.98
2.12
10.56
4.75 – 5.25
Pass
Total Power Supply Loading
172W
 

 

110VAC - Total Load at 472W which is 56% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.29
7.79
25.63
3.135 – 3.465
Pass
+5V0
5.01
9.19
46.04
4.75 – 5.25
Pass
+12V0(1)
12.07
8.01
96.68
11.4 – 12.6
Pass
+12V0(2)
12.07
8.02
96.80
11.4 – 12.6
Pass
+12V0(3)
12.05
7.99
96.28
11.4 – 12.6
Pass
+12V0(4)
12.05
7.99
96.28
11.4 – 12.6
Pass
-12V0
11.96
0.36
4.31
10.8 – 13.2
Pass
+5VSB
4.96
2.12
10.51
4.75 – 5.25
Pass
Total Power Supply Loading
472W
 

 

110VAC - Total Load at 809W which is 96% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.26
17.77
51.41
3.135 – 3.465
Pass
+5V0
4.97
19.10
94.93
4.75 – 5.25
Pass
+12V0(1)
12.04
13.49
162.42
11.4 – 12.6
Pass
+12V0(2)
12.04
13.48
162.30
11.4 – 12.6
Pass
+12V0(3)
12.02
13.46
161.79
11.4 – 12.6
Pass
+12V0(4)
12.02
13.45
161.67
11.4 – 12.6
Pass
-12V0
11.94
0.36
4.30
10.8 – 13.2
Pass
+5VSB
4.90
2.10
10.29
4.75 – 5.25
Pass
Total Power Supply Loading
809W
 

 

Testing @ 240VAC:

 

 

240VAC - Total Load at 172W which is 20% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.31
3.09
10.23
3.135 – 3.465
Pass
+5V0
5.05
4.66
23.53
4.75 – 5.25
Pass
+12V0(1)
12.09
2.56
30.95
11.4 – 12.6
Pass
+12V0(2)
12.09
2.56
30.95
11.4 – 12.6
Pass
+12V0(3)
12.08
2.55
30.80
11.4 – 12.6
Pass
+12V0(4)
12.08
2.55
30.80
11.4 – 12.6
Pass
-12V0
11.98
0.36
4.31
10.8 – 13.2
Pass
+5VSB
5.00
2.12
10.60
4.75 – 5.25
Pass
Total Power Supply Loading
172W
 

 

240VAC - Total Load at 472W which is 56% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.28
7.80
25.58
3.135 – 3.465
Pass
+5V0
5.00
9.20
46.00
4.75 – 5.25
Pass
+12V0(1)
12.06
8.01
96.60
11.4 – 12.6
Pass
+12V0(2)
12.06
8.03
96.84
11.4 – 12.6
Pass
+12V0(3)
12.05
8.00
96.40
11.4 – 12.6
Pass
+12V0(4)
12.05
7.99
96.28
11.4 – 12.6
Pass
-12V0
11.95
0.36
4.30
10.8 – 13.2
Pass
+5VSB
4.95
2.12
10.49
4.75 – 5.25
Pass
Total Power Supply Loading
472W
 

 

240VAC - Total Load at 811W which is 96% of Rated Maximum Output Power.

PSU
DC Line
Measured
Voltage(V)
Measured
Current (A)
Load Power
(W)
ATX12V V Limits
(V)
Pass/Fail
+3V3
3.26
15.91
51.87
3.135 – 3.465
Pass
+5V0
4.96
19.20
95.23
4.75 – 5.25
Pass
+12V0(1)
12.03
13.52
162.64
11.4 – 12.6
Pass
+12V0(2)
12.03
13.52
162.64
11.4 – 12.6
Pass
+12V0(3)
12.02
13.51
162.39
11.4 – 12.6
Pass
+12V0(4)
12.01
13.50
162.13
11.4 – 12.6
Pass
-12V0
11.93
0.36
4.29
10.8 – 13.2
Pass
+5VSB
4.89
2.10
10.27
4.75 – 5.25
Pass
Total Power Supply Loading
811W
 

 

 

These are some of the best results I have seen from any power supply I have so far tested. The +12V rails at no time dropped below 12.0V, which is really excellent. Absolutely no problems so far.

Testing (Continued):

Efficiency and Power Factor:

 

 

 

 

 

 

 

 

 

 

Output & Efficiency at 110VAC
DC Load (W)
AC Load (VA)
AC Load (W)
PF
Efficiency (%)
Pass/Fail
0
10
0
0.02
N/A
N/A
172
210
210
1.0
82
Pass
472
568
570
1.0
83
Pass
809
1035
1036
1.0
78
Pass

 

Output & Efficiency at 240VAC
DC Load (W)
AC Load (VA)
AC Load (W)
PF
Efficiency (%)
Pass/Fail
0
43
1
0.03
N/A
N/A
172
219
206
0.94
83
Pass
472
557
555
0.99
85
Pass
811
1001
997
0.99
81
Pass

 

The 80 PLUS Bronze certification requires the Antec Signature 850W to run at greater than or equal to 82-85-82 percent efficiency at 20-50-100 percent of rated power output. While the specification has been partially met, I think I can allow a pass at 240VAC, there is a failure as you see can above at 110VAC. The power supply did, however, meet the ATX12V minimum required efficiency, and I have therefore given the power supply an overall pass in this section.

The 80 PLUS certification also requires the power supply to maintain a power factor PF of 0.9 or better, no problems here.

These are some of the best efficiency figures I have seen so far and go some way in explaining the use of a smaller 80mm cooling fan. High efficiency = less heat.

 

AC Ripple on DC Outputs:

 

All AC ripple measurements are made at the maximum load, and were found to be virtually identical for 110VAC and 240VAC input. I have therefore included oscilloscope screenshots for 240VAC only.

 

AC ripple on 3V3 rail.

AC ripple on 5V0 rail.

AC ripple on 12V rail.

 

Antec Signature 850W AC Ripple/Noise Measurements

DC Output
3V3
5V0
12V1
12V2
12V3
12V4
-12V
5VSB
Ripple (mV p-p)
8
10
13
13
13
13
20
10
Pass/Fail
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass

 

Impressive figures! These really are very low and will be hard to equal, let alone improve.

Onward...

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 Loading
Temp In (°C)
Temp Out (°C)
Δ Temp (°C)
Fan Speed (RPM)
172W
21.1
29.8
8.7
704
472W
22.0
36.8
14.8
1105
811W
20.5
42.4
21.9
3084

 

The noise level from this unit was at no time loud, and compared favorably with other high-end power supplies on the market. It was very difficult to hear the fan at 704 and 1105 RPM but the noise level increased noticeably at 3084 RPM which is to be expected. The pulse width modulated supply of the fan will provide more accurate control of the speed but whether it makes a difference to noise levels I have yet to be convinced. I can say however, that this power supply, installed in the majority of systems out there, at low to medium power consumption will probably prove to be extremely quiet. Noise levels are, of course, my personal opinion, and what I may consider quiet could quite easily be considered noisy by other people.

Conclusion:

Environmental Factors:

With 80 PLUS Bronze certification, on which I have a few things to say later, and almost unity power factor, the Antec Signature 850W will play a small part in cutting your energy bills. The Antec Signature 850W complies with RoHS regulations which isn't really unusual these days. Packaging on the Signature could have been better from an environmental point of view, there are alternatives to foam and plastic available, but I have to say it does look the part and perhaps it's a little unkind to compare it with a shoe box.

Price Per the Watt:

Power Supply Antec Signature 850W at $229.99 = $0.27/Watt (September 2008)

A minor disappointment was its failure to comply with its 80 PLUS Bronze certification but the Signature can boast the best efficiency results I have ever seen which will be difficult to better. If you are looking for a power supply to run your two 9800 GX2 graphic cards in SLI, well look no further. I was able to verify its certification by cross-referencing Nvidia's list of certified components.

The AC ripple/noise levels are amongst the best I have seen and enable the Signature to produce DC rails of excellent quality. This is the first power supply I have tested that derives the 3V3 and 5V0 rails via DC to DC regulators and perhaps this can, to some extent, explain the low AC ripple/noise levels.

The cooling fan is bearly audible up to approximately 500W (700 RPM), which is more than enough for the average user. Over 600W and fan speed increases significantly as it heads up toward 850W and 3000 RPM but I think this is inevitable with a cooling fan of only an 80mm diameter.

I would highly recommend the Antec Signature 850W to anyone considering high end graphics cards in SLI or Crossfire but perhaps it's a little expensive and over powered for the majority of users. If price is not an issue and you are looking for a high quality power supply, almost silent up to approximately 500 - 600W, then the Antec Signature 850W will I'm sure, prove to be a wise investment. Despite the failure to meet the claimed 80 Plus Bronze efficiency levels, the efficiency is still very good and I have no hesitation in giving the Antec Signature 850W an OCC Gold Award.

 

Pros:

 

Cons: