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 | |
100W
|
1.56
|
3.36
|
1.77
|
5.05
|
6.69
|
11.97
|
0.5
|
5.02
|
0.20 | -12.12 |
200W
|
3.17
|
3.33
|
3.42
|
5.05
|
13.54
|
11.95
|
1.0
|
5.00
|
0.30 | -12.15 |
400W
|
6.15
|
3.30
|
7.11
|
5.03
|
27.61
|
11.92
|
1.5
|
4.97
|
0.50 | -12.17 |
600W | 9.43 | 3.28 | 10.75 | 5.00 | 41.32 | 11.87 | 2.0 | 4.95 | 0.60 | -12.19 |
800W
|
13.22
|
3.26
|
15.03
|
4.97
|
55.34
|
11.83
|
2.5
|
4.92
|
0.80 | -12.21 |
The TR2 800W delivered stable load regulation across the board remaining firmly within +/-3% of the nominal voltage.
Thermaltake TR2 800W | Maximum Load |
857W |
We managed to get the PSU to hit 857W before it would shut down. delivering around 57W more than the rated specifications.
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 | |
760W | 1.0 | 3.28 | 1.0 | 5.02 | 60.0 | 11.74 | 0.2 | -12.08 | 0.50 | 5.01 |
165W | 15.0 | 3.25 | 18.0 | 4.96 | 2.0 | 11.96 | 0.2 | -12.12 | 0.50 | 4.95 |
Cross loading results fall within parameters, with only a slight drop on the +12V when loaded with 60A. +3.3V and +5V hold voltage well.
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 |
100W | 20 | 20 | 30 | 20 |
200W | 25 | 20 | 35 | 20 |
400W | 30 | 25 | 45 | 25 |
600W | 35 | 30 | 60 | 25 |
800W | 35 | 30 | 70 | 30 |
Noise suppression isn't the best we have seen, however it does fall within the ripple tolerance guidelines. The +3.3V output achieved a maximum of 35mV under full load. The +12V output peaked at 70 mV under full load.
Efficiency (%)
|
|
100W
|
85.57
|
200W
|
86.32
|
400W
|
87.74
|
600W
|
86.65
|
800W | 85.89 |
For a 80 Plus Bronze specified unit, these results are very good, showing a maximum efficiency rating just below 88 percent. At maximum load this drops to just under 86%, which is again, a great 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 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)
|
|
100W
|
29.5
|
200W
|
31.2
|
400W
|
33.4
|
600W
|
37.9
|
800W | 42.3 |
The power supply doesn't generally emit a lot of noise (under 40% of output power), until it is loaded into the last 30% of the rated power output, when the fan spins up dramatically to deal with the rising temperatures.
Between 600W and 800W the noise emissions quickly rise, to a maximum level rated just over 42 dBa. If you need a power supply to constantly deliver 700W+ then the noise levels might be intrusive long term.
Temperature (c)
|
||
Intake
|
Exhaust
|
|
100W
|
36
|
38
|
200W
|
36
|
42
|
400W
|
38
|
45
|
600W
|
39
|
53
|
800W
|
41
|
57
|
The temperatures rise to 57C when fully loaded. These could have been reduced if the design had used larger heatsinks.
Maximum load
|
Efficiency
|
857W
|
83.7%
|
For those interested, we measured efficiency when stressing the unit to breaking point. Almost 84% at 857W … hardly practical, but interesting regardless.
Must be one of the cheapest 800W 80 plus bronze units on the market.
Shame its not modular too.
I like the price, but a non modular supply is hard to live with. I bought one a few months ago and I hate all the cables I have to hide. You can never really hide them that well either, depending on the case.
Next one I buy will be modular, even if it costs £20 more.
Thats really very good indeed. love it. great price to achieve for high ouput and 80 bronze
Thermaltake get it right, but not often. This is a pretty tried and tested design with nothing dramatically new to ‘mess up’.
Seems like a good product at the right price.
Can you change the fan connector via plug and play?
on the pictures you cant see where the cable is going.