Introduction
Thermaltake Purepower 430 W NP, which is also known by other names like W0070, TR2-430W and XP550 NP, is one of the simplest and cheapest power supplies from Thermaltake. In this review we completely disassembled this unit and tested to see if it can really deliver 430 W. Check it out.
In the past we took an in-depth look on this power supply when it was still called TR2-430W. Because now we look power supplies into much more details and also perform load tests, this is a completely new review of this power supply, written from scratch.
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Figure 1: Thermaltake Purepower 430W NP.
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Figure 2: Thermaltake Purepower 430W NP.
As you can see, this power supply uses two 80-mm fans, one on the front and another on the rear of the unit. We prefer the design using a big 120- or 140-mm fan as it provides not only a better airflow but the power supply produces less noise, as the fan can rotate at a lower speed in order to produce the same airflow as an 80-mm fan.
The first thing you have to be careful about this power supply is that on its box Thermaltake says this power supply has a PFC circuit, which is not the case. In fact the “NP” letters on the name of the model stands for “No PFC”. PFC is optional and is present only on the W0069 model. The absence of the PFC circuit means only that Thermaltake can’t sell this unit in Europe (read more about PFC on our Power Supply Tutorial).
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Figure 3: The box says this power supply has PFC.
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Figure 4: The box says this power supply has PFC.
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Figure 5: End of the mystery. It is optional, not present on the reviewed model.
As for efficiency, Thermaltake says that this product has a 65% minimum efficiency, which is a low value for today’s standards. Of course we will measure efficiency during our tests. Keep in mind that more expensive power supplies have an efficiency of at least 80%. The higher the efficiency the better – an 80% efficiency means that 80% of the power pulled from the power grid will be converted in power on the power supply outputs and only 20% will be wasted. This translates into less consumption from the power grid (as less power needs to be pulled in order to generate the same amount of power on its outputs), meaning lower electricity bills.
This power supply comes with five peripheral power cables: one auxiliary power cable for video cards with 6-pin connector, two cables containing three standard peripheral power connectors and one floppy disk drive connector, one cable containing three standard peripheral connectors and one cable containing two SATA power connectors.
We didn’t like the way the peripheral connectors were installed on this unit. Instead of using the traditional configuration where the cable coming from inside the power supply is connected to the last connector on the cable, on this power supply this cable is connected to the middle connector, and the other two connectors are connected there as well.
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Figure 6: How peripheral connectors are installed.
The number of available connectors is enough for a mainstream user that won’t have more than two SATA devices willing to build an entry-level or mainstream PC with a good video card. However, users with more than two SATA devices (i.e. more than two hard drives) will need to use adaptors.
The main motherboard cable uses a 20/24-pin connector, and this power supply has one ATX12V connector, not coming with an EPS12V connector.
On the aesthetic side Thermaltake used nylon sleeving only on all cables, but this protection doesn’t from inside the power supply housing.
A more concerning problem is that wires used on the video card auxiliary power cable and on the ATX12V cable are 20 AWG, i.e. thinner than recommended. All other wires are 18 AWG, though.
This power supply is manufactured by HEC (Compucase) and on their website we couldn’t find any power supply that is identical to Purepower 430W, so it is an exclusive model manufactured only for Thermaltake.
A Look Inside Purepower 430W NP
We decided to disassemble this power supply to see how it looks like inside, what is the design used and what components are used. Please read our Anatomy of Switching Power Supplies tutorial to understand how a power supply works inside and to compare this power supply to others.
In this page we will have an overall look, while on the next page we will discuss in details the quality and rating of the components used.
The first impression we had when opening this power supply was that we were in front of a very low-end (“generic”) unit that was put inside a nice housing as the printed circuit board was too small for the size of the housing, as you can see on Figure 7. Let’s see if this was just an impression or if there is some truth about our hunch.
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Figure 7: Overall look.
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Figure 8: Overall look.
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Figure 9: Overall look.
Transient Filtering Stage
As we mentioned on other articles and reviews, the first place we like to take a look when opening a power supply to have a hint about its quality is its filtering stage. The recommend components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor) and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components than that, usually removing the MOV and the first coil.
This power supply has one X capacitor more than needed.
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Figure 10: Transient filtering stage.
A very interesting feature from this power supply is that its fuse is inside a fireproof rubber protection. So this protection will prevent the spark produced on the minute the fuse is blown from setting the power supply on fire.
Now let’s have a more detailed discussion on the components used on Purepower 430W NP.
Primary Analysis
We were very curious to check what components were chosen for the power section of this power supply and also how they were set together, i.e. the design used. We were willing to see if the components could really deliver the power announced by Thermaltake.
The design used here is different from the one used by other low-end power supplies we reviewed recently: Seventeam ST-420BKV0, Huntkey Green Star 450 W and Kingwin ABT-450MM. These three power supplies use two regular NPN BJT power transistors on the switching section under a half-bridge configuration, while Thermaltake Purepower 430 NP uses one power MOSFET transistor in single transistor forward configuration.
The use of MOSFET transistor is better than using regular NPN transistors, but since this power uses only one transistor and the other power supplies use two, we will only be able to judge which configuration is better during our actual performance tests.
This power supply uses one GBU806 rectifying bridge on its primary stage, which can deliver up to 8 A (rated at 100º C). This component is clearly overspec'ed: at 115 V this unit would be able to pull up to 920 W from the power grid; assuming 80% efficiency, the bridge would allow this unit to deliver up to 736 W without burning this component. Of course we are only talking about this component and the real limit will depend on all other components from the power supply.
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Figure 11: Rectifying bridge.
As we said, this power supply uses only one transistor on its switching section, an STP10NK60Z power MOSFET transistor in single-transistor forward configuration. It can deliver up to 10 A at 25º C or 5.7 A at 100º C. You can see it on the right-hand side of Figure 12. The transistor on the left-hand side is the transistor used on the +5VSB power supply, which is independent from the rest of the power supply.
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Figure 12: Switching transistor (on the right side).
Secondary Analysis
This power supply uses a mix between new and obsolete designs, showing us that the manufacturer instead of creating a new design from scratch adapted an old design.
The main difference between this power supply and newer (and better) models is how power is distributed. This power supply was projected when most of the power drawn by the computer was concentrated on the +5 V line and not on the +12 V line like it is today. We can say this because it uses a rectifier with lower specs for the +12 V line and the rectifier with higher specs for the +5 V line.
The +12 V rectifier is connected like in old power supplies (half-bridge design). The maximum theoretical current under this design is a simple addition of the maximum current each diode can deliver. Since the +12 V output is produced by one MBR20100CT Schottky rectifier, which can deliver up to 20 A (10 A per internal diode, measured at 133º C), the maximum theoretical power the +12 V output can deliver is of 240 W. The maximum current this line can really deliver will depend on other components. As mentioned, this output supports less current/power than required by today's standards.
The +5 V output is produced by one MBR4045PT Schottky rectifier, which support up to 40 A (20 A per internal diode, measured at 125º C). The maximum theoretical current the +5 V output can deliver depends on the duty cycle used. If this power supplies uses a 30% duty cycle (which is a typical value), the maximum current would be 29 A [20 A/(1 - 0.30)], with a maximum power of 143 W. Of course the maximum current (and thus power) this line can really deliver will depend on the other components.
Then it comes how +3.3 V is produced. It has a separated rectifier like all current power supplies, but the output of this rectifier is +5 V, so it uses a voltage regulator to decrease this +5 V to +3.3 V. This is a mix between old and new designs. Old ATX power supplies generated their +3.3 V output by using a voltage regulator connected to the +5 V output. New power supplies have a completely separated rectifier. So this power supply uses a mix of these two approaches.
The +3.3 V output is produced by one MBR3045PT Schottky rectifier, which supports up to 30 A (15 A per diode, measured at 105º C). Using the same math presented above, this rectifier could in theory deliver up to 21 A or 71 W. Like we explained, the output of this rectifier is connected to a +3.3 V voltage regulator, controlled by an IPP09N03LA power MOSFET transistor, which is capable of handling up to 50 A at 25º C or 46 A at 100º C. Since in configurations like this the component with the lower current limit is the one that limits the circuit, in theory the +3.3 V output from this power supply can deliver up to 21 A or 71 W (if the duty cycle from the waveform applied on the rectifying diode is really 30%). As we explained the real limit depends on other factors.
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Figure 13: +12 V, +5 V and +3.3 V rectifiers.
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Figure 14: Power MOSFET transistor used on the +3.3 V regulator circuit.
As you can see on Figure 14 this power supply has a thermal sensor attached to its secondary heatsink. This sensor is used to control the fan speed according to the power supply internal temperature.
On this power supply the big electrolytic capacitors from the voltage doubler are from Teapo (a Taiwanese company) and rated at 85º C, while the electrolytic capacitors from the secondary are from Teapo and Su’scon (another Taiwanese company) and rated at 105º C.
Power Distribution
On Figure 15 you can see this power supply label containing all its power specs.
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Figure 15: Power supply label.
As you can see it has only one +12 V rail, since it is based on an old design, as we explained on previous page.
Let’s now see if this power supply can really deliver 430 W of power.
Load Tests
We made several tests with this power supply as described in the article Hardware Secrets Power Supply Test Methodology. All the tests described below were taken with a room temperature between 46º C and 48º C. During our tests the power supply temperature was between 51º C and 54º C.
First we tested this power supply with five different loads patterns, trying to pull around 20%, 40%, 60%, 80% and 100% of its labeled maximum capacity (under “% Max Load” we list the actual percentage that was used), watching how the reviewed unit behaved under each load. On the table below we list the load patterns we used and the results for each load.
Since this power supply has only one +12V rail this time we connected all connectors from the power supply together on the +12V1 input from our load tester.
If you add all the powers listed for each test you may find a value different from what posted under “Total” below. Since each output can have a slight variation (e.g. +5 V output working at 5.10 V) the actual total amount of power being delivered is slightly different from the calculated value. On “Total” row we are using the real amount of power being delivered, as measured by our load tester.
Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
+12V1 | 5 A (60 W) | 8 A (96 W) | 14 A (168 W) | 16 A (192 W) | 18 A (216 W) |
+5V | 2 A (10 W) | 8 A (40 W) | 10 A (50 W) | 18 A (90 W) | 24 A (120 W) |
+3.3 V | 2 A (6.6 W) | 8 A (26.4 W) | 10 A (33 W) | 16 A (52.8 W) | 23 A (75.9 W) |
+5VSB | 1 A (5 W) | 1 A (5 W) | 1 A (5 W) | 1.5 A (7.5 W) | 2 A (10 W) |
-12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.8 A (9.6 W) |
Total | 87.8 W | 174.6 W | 262.9 W | 348.8 W | 431.5 W |
% Max Load | 20.4% | 40.6% | 61.1% | 81.1% | 100.3% |
Result | Pass | Pass | Pass | Pass | Fail |
Voltage Stability | Pass | Pass | Pass | Pass | Fail |
Ripple and Noise | Pass | Pass | Pass | Pass | Fail |
AC Power | 115 W | 227 W | 350 W | 498 W | Fail |
Efficiency | 76.3% | 76.9% | 75.1% | 70.0% | Fail |
When we tried running test number 5, the power supply wouldn’t turn on, showing us that its over power protection (OPP) was in action and configured at a value that was lower than the power supply maximum capacity.
So we tried to change the configuration we had set for test number five to try to see how much power we could really pull from this unit. Starting from test number four, the maximum we could do was to increase one amp at +3.3 V from 16 A to 17 A, making the power supply to deliver only around 355 W (under this configuration it was pulling 510 W from the wall, so efficiency was 69.6%). Any other configuration we tried above that the power supply would work outside its specs, especially noise.
At test number four noise level for +12 V was 83.4 mV, for +5 V was 35 mV and for +3.3 V was 25.6 mV. By just increasing one amp at +3.3 V as we explained, noise level at +12 V jumped to 117 mV, at +5 V jumped to 50 mV and at +3.3 V stayed at 31.6 mV. As you can see these number are already touching the noise maximum level (120 mV for +12 V and 50 mV for +5 V and +3.3 V).
When we tried increasing one amp at +12 V noise jumped to 190 mV and skyrocket to 680 mV when we tried pulling 18 A from it – and, remember, according to the power supply label +12 V could deliver 18 A.
The conclusion is that according to our methodology Thermaltake Purepower 430 W NP isn’t a 430 W power supply, but a 350 W model! We also could only pull 16 A from its +12 V output, while the label says the limit is 18 A.
On the other hand, this power supply has its over power protection (OPP) circuit in action, which prevented this power supply from burning when we pulled more power that it could handle – what didn’t happen with Huntkey Green Star 450 W, which is also a power supply labeled at 450 W that can only deliver 360 W.
Below you can see noise level when we were pulling 355 W from this power supply.
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Figure 15: Noise level at +12 V with power supply delivering 355 W.
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Figure 16: Noise level at +5 V with power supply delivering 355 W.
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Figure 17: Noise level at +3.3 V with power supply delivering 355 W.
Voltage regulation during our tests one thru four was excellent, with all outputs within 3% of their nominal voltages – ATX specification defines that all outputs must be within 5% of their nominal voltages (except on -12 V where the limit is 10%).
This power supply provided efficiency below 80%, reaching 70% when we pulled the maximum about of power it could deliver – 350 W. Definitely there are better products around. Kingwin ABT-450MM, for example, is a competing cheap low-end power supply that could maintain an efficiency above 80% when pulling 40% and 60% of its load (i.e. between 180 W and 270 W).
Short-circuit protection was tested and was working just fine.
This power supply fans run very slowly when the power supply is cold and they started spinning faster as soon as the power supply reached 28º C, with an obvious increase on the noise generated, but not to the point we would categorize as disturbing.
Main Features
Thermaltake Purepower 430 W NP power supply main specs include:
- ATX12V 1.3
- Nominal labeled power: 430 W.
- Measured maximum power: 355 W at 48º C.
- Labeled efficiency: 65% minimum
- Measured efficiency: Between 69.6% and 76.9% at 115 V.
- Active PFC: No.
- Motherboard Connectors: One 20/24-pin connector and one ATX12V connector.
- Peripheral Connectors: one auxiliary power cable for video cards with 6-pin connector, two cables containing three standard peripheral power connectors and one floppy disk drive connector, one cable containing three standard peripheral connectors and one cable containing two SATA power connectors.
- Protections: over voltage (OVP), over power (OPP) and short-circuit (SCP). Information provided by the manufacturer, see text for actual testing of these features.
- Warranty: Five years.
- Real manufacturer: HEC (Compucase)
- More Information: http://thermaltakeusa.com
- Average price in the US*: USD 40.00
* Researched at Shopping.com on the day we published this review.
Conclusions
This is an old ATX power supply where the manufacturer added a 24-pin motherboard connector, SATA power cables and a PCI Express auxiliary power cable to make it compatible with computers available today. Simply updating the cables doesn’t make this power supply an updated product. This is so true that this power supply is listed as ATX12V 1.03 by Thermaltake, and not as ATX12V 2.x, despite the presence of the 24-pin motherboard connector and the 6-pin PCI Express auxiliary power cable for video cards.
The main problem with this power supply is that it can’t deliver its labeled power. It is, in fact, a 350 W power supply.
This same thing happens with Huntkey Green Star 450 W, but at least this power supply from Thermaltake has all its overload protection in place and won’t explode like this model from Huntkey.
If these power supplies can’t deliver their labeled power couldn’t we sue the manufacturer on the grounds of false advertisement? Unfortunately no, as the manufacturers can claim they use a different methodology to label their product (for example, measuring power at 25º C and stating peak power and not continuous power). We, however, think that the correct methodology should be one similar to ours (temperature between 45º C and 50º C, continuous power).
You could buy it as if it were a 350 W unit, but when we pulled 355 W from this power supply noise level was touching the maximum admissible limit and efficiency was at 69.6%. With other load patterns the maximum efficiency we saw was 76.9%.
Our conclusion is pretty simple: don’t buy this power supply. If you are on budget and are looking for a cheap power supply on the 450 W range for your entry-level PC, Kingwin ABT-450MM is a better option.
Originally at http://www.hardwaresecrets.com/article/332
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