The Candidates

The following review is another look at seeing if you really get what you pay for—or if you can get high quality without breaking the bank. For this roundup we have three power supplies rated at 550W, but with different prices. Will the most expensive unit deliver the best results? Can a cheaper product deliver the quality you need, and make up the difference by trimming the packaging and contents? Read on to find it out.

The first product comes from Techsolo Europa B.V., a brand from the Netherlands. Our US readers most likely haven't encountered the brand, but they sell cheap power supplies, PCI controller cards, and cases in Italy, Germany and Poland. We've got their Techsolo Black Mamba STP-550, representative of many budget power supplies. In Germany this PSU sells for around 30€ (39.18$; Oct. 22, 2010). Imagine our surprise to find that Techsolo advertises CE-certification as a "feature" (you need CE to sell power supplies in Europe). The PSU has passive PFC as well as a "silent" 140mm fan for cooling. More "interesting" features are high stability on  all rails (+3.3V, +5V, +12V) and an On/Off Switch. It just keeps getting better! This PSU is not available in the US, but it's still a nice representative of the low-end and frequently outdated junk you can still find floating around—or perhaps included with an inexpensive case. You'll note that there's no 80 Plus certification on this one, which isn't too surprising considering the target market.

The second unit is a power supply from OCZ Technology Group. They're now famous for their SSDs and RAM, but they have many power supplies as well. Today we'll look at the OCZ Fatal1ty OCZ550FTY, priced at 64.99$ online—a $26 upgrade from our Techsolo sample. It looks like the Red Mist of power supplies with a red LED-fan and label. Otherwise, OCZ is using the same topology from their ModXStream Pro 500W with a few changes in the details. The 80 Plus certification is standard for any decent PSU today, but maybe that's enough to beat up on the Techsolo. Another advantage is the modular cables, which is a nice feature for the price.

The most expensive but potentially best power supply in this small comparison test is the new Antec TruePower New TP-550. You can get the product for 89.99$ online, another $24 premium over the OCZ and over twice the cost of the Techsolo. Antec uses Japanese capacitors, a DC-to-DC Converter for the smaller rails, a PWM-fan from ADDA for cooling, and a partially modular cable management. With 80 Plus Bronze certification, the TruePower New should be more efficient than the other two power supplies, but is it clearly better?

As usual we will look at the voltage regulation and quality, noise levels, and check out the internal design. Over the course of our roundup, we'll find out if these PSUs perform according to expectations, or if there are a few surprises in the mix.

Techsolo Black Mamba STP-550

Techsolo keeps things simple with their packaging and extras. You get a standard power cable (for Europe), four screws, some cable ties, and a short user manual. The best-case hope for the Techsolo Black Mamba is that we'll get an "ultra silent" snake that can deliver the full rated power. I wouldn't bet on it, but more than one user has been tempted into going the cheap route on a PSU. At worst, the Black Mamba is a noisy blindworm that dies at 50% load, but most likely it will land somewhere in between those extremes.

The red (already mentioned and super-duper) power switch stands in contrast to the black case design. The fan grill and the cable sleeving are black too and the housing of the ATX 2.2-PSU is 14cm long. Considering the cost, the PSU actually looks decent—even cheap cable sleeving is a bump up over unsleeved cables, after all.

Cables and Connectors
Fixed	Main	24-pin 40cm
	ATX12V/EPS12V	4+4-pin 45cm
	PCIe	6-pin 45cm
	Peripheral	3x PATA 40-70cm + Floppy 15cm
		3x SATA 40-70cm / 3x SATA 40-70cm

The main cables are very short at less than 50cm, and there are only six SATA and three Molex power connectors along with a single PEG connector for graphic cards—the latter seems particularly skimpy. We don't want to be too quick to judge, but this is not a good configuration for a 550W PSU; it looks more like a 400W PSU. We'll get into more details on the next page.

Shenzhen Xin Wang Electronics Co., LTD. makes the fan, one of those nameless (despite the length of their name) Chinese companies. The 140mm fan needs fewer amps than the other fans in this roundup and it has nine fan blades. Will it be silent, and can it keep the PSU cool? We'll find out in a minute.

Techsolo Black Mamba Internals

The internals consist of small heatsinks, a small transformer, and a big and noisy PFC-choke in the bottom right corner. The undersized bridge rectifier has no heatsink and the protective ground wire is connected to a mounting screw of the main PCB—bad idea! If an engineer or other employee disconnects the main PCB, there is no more ground contact.

There are four Y- and two X-caps as well as two current compensated coils in the EMI filtering stage, missing a MOV. Can you see the wire cross-section of phase and neutral conductor? It doesn't look like 550W. Things are looking black for our Black Mamba!

Techsolo Voltage Regulation and Quality

+3.3V regulation
Load	Voltage
10%	3.35V (+1.52%)
20%	3.32V (+0.61%)
50%	3.23V (-2,12%)
80%
100%
110%

 

+5V regulation
Load	Voltage
10%	5.06V (+1.2%)
20%	4.99V (-0.2%)
50%	4.79V (-4.2%)
80%
100%
110%

 

+12V regulation
Load	Voltage 12V1/V2
10%	12.01V (+0.17%)/ 12.02V (+0.18%)
20%	11.99V (-0.08%)/ 12.02V  (+0.18%)
50%	11.93V (-0.58%)/ 11.90V (-0.83%)
80%
100%
110%

Uh oh! As you can see, the PSU died after 50% load—the two main switches exploded! All the rails are still within specification at 50%, but you can see large voltage drops and +5V is close to the limit of -5%. +12V stays stable with more than 11.90V at all tested loads, but naturally the failure at 80% load is a major black mark.

Ripple and Noise

+3.3V ripple quality
Load	Ripple and noise
10%	7.20mV
20%	7.70mV
50%	14.30mV
80%
100%
110%

 

+5V ripple quality
Load	Ripple and noise
10%	7.90mV
20%	11.70mV
50%	21.40mV
80%
100%
110%

 

+12V ripple quality
Load	Ripple and noise
10%	19.50mV
20%	32.90mV
50%	63.70mV
80%
100%
110%

The ripple and noise results aren't that bad, but the ripple on +12V could be lower. 64mV is half of the spec, but we've seen worse results there. In fact, some $150 PSUs aren't better here, but deliver the full power and shut down if there is a problem. Again, the failure of the Techsolo at 80% is a key point; it may kill your hardware, so stay away from this product.

Techsolo Noise Levels and Efficiency

Sound Pressure Level
Load	dB(A)
10%	22
20%	23
50%	28
80%
100%
110%

Wow! Our "silent" fan is moderately loud and hit nearly 30dB at 50% load, but even worse is the PFC-choke that's singing like a castrated dog. If you want to have a silent computer, please buy another power supply and protect your ears.

Efficiency and PFC

230VAC, 50Hz
Load	Efficiency	PFC
10%	68%	0.490
20%	74%	0.505
50%	73%	0.556
80%
100%
110%

 

115VAC, 60Hz
Load	Efficiency	PFC
10%	-	-
20%	-	-
50%	-	-
80%
100%
110%

The efficiency hit a maximum of 74%, with under 70% at low load. There is no real power factor correction on display, and we're nowhere near 80 Plus certification. Passive PFC should be good enough to reach 0.700-0.800, but we only hit 0.55 before the PSU died.

Hopefully we've managed to convince you that if nothing else, getting one of the ultra-cheap power supplies is not something you want to do, particularly if you plan on running at anything close to the rated output. Our "550W" unit was able to function as a low-quality 275W PSU before giving up the ghost, but the 73% efficiency at that load means we're wasting 100W of power. Even a basic 80 Plus PSU would save 30-40W, which means if you're using the PC eight hours per day you would make up the difference in price within two years—and that's not even taking into account the cost of replacing hardware should the unit kill your other components in a fit of rage. In short: stay away, because this Black Mamba is poised to strike (and not in a good way)!

OCZ Fatal1ty OCZ550FTY

The OCZ Fatal1ty comes with the usual assortment of parts: you get a users manual, a US/UK/Europe power cord (depending on your location), and the necessary mounting screws. In addition, the power supply has cable management ("EZMod Technology for custom cabling"), and the modular cables are placed in a separate bag. The distinctive product features consist of a red LED-fan and active PFC—the latter is not that remarkable, but it's a step up from budget PSUs like the Techsolo. OCZ also makes mention of the 135mm fan and 80 Plus certification. The marketing tells us to "get the Gear used by the Pros", referencing the infamous John "Fatal1ty" Wendel of Quake 3 fame [Ed: has he even done much recently?], and we can only hope the pros use high quality power supplies. OCZ offers a 3-year-warranty with support in their forums.

The varnish is shiny, the ventilation holes are tiny, and when the fan is off you can see almost transparant fan blades and parts of the internal design. The depth of the housing is 16cm, which is okay for a 550W power supply with cable management. There is a large power switch in front of the PSU, but no need to mention this as a feature on the packaging.

Cables and Connectors
Fixed/Modular	Main	24-pin 45cm
	ATX12V/EPS12V	4+4-pin 45cm / 4-pin 45cm
	PCIe	6/8-pin 50cm / 6-pin 50cm
	Peripheral	3x PATA 45-75cm / 3x PATA 45-75cm + Floppy 15cm
		3x SATA 45-75cm / 3x SATA 45-75cm

The main cables could be longer than 45cm for use in large cases, but this will work fine otherwise. The 4+4-pin ATX12V and one more 4-pin ATX12V is not bad for a 550W PSU. Six SATA and six Molex connectors are more than enough for common PC configurations, and the floppy connector increases the maxmium cable lenght up to 90cm (but only if you need a mini-4-pin Molex, obviously). Finally, the 6/8-pin and 6-pin PEG connectors make for a reasonable 550W PSU setup.

OCZ continues to use a Globe Fan fan with a double ball bearing, which is partially covered by ducting. The fan needs 0.33 amps and has eleven transparent fan blades.

OCZ Fatal1ty Internals

Here we have a typical Sirtec design with three heatsinks and so-so soldering quality. The EMI filtering is equipped well, but there is no MOV. It's nice to see that there are no Transcend Electrolytic capacitors from China; now they use Teapo, even if they have chosen the cheap models. The Teapo LH doesn't have the longest lifetime and lowest ESR; however, we've never detected a problem with Teapo in power supplies.

Note that the X-cap behind the entrance is isolated, since there is not much space between the entrance and the heatsink in the secondary circuit. In summary, the Fatal1ty has better caps and better insultion than the OCZ ModXStream Pro. Nevertheless, the improvements are not enough to really make this a new product. It's a decent design with a reasonable price, but despite the Fatal1ty name you won't get any extra frames per second. Now let's see how it performs in our tests.

OCZ Voltage Regulation and Quality

+3.3V regulation
Load	Voltage
10%	3.39V (+2.72%)
20%	3.38V (+2.42%)
50%	3.34V (+1.2%)
80%	3.30V (0%)
100%	3.28V (-0.61%)
110%	3.24V (-0.91%)

 

+5V regulation
Load	Voltage
10%	5.03V (+0.6%)
20%	5.02V (+0.4%)
50%	4.98V (-0.4%)
80%	4.94V (-1.2%)
100%	4.91V (-1.8%)
110%	4.90V (-2%)

 

+12V regulation
Load	Voltage
10%	12.37V (+3.08%)
20%	12.34V (+2.83%)
50%	12.29V (+2.42%)
80%	12.25V (+2.08%)
100%	12.21V (+1.75%)
110%	12.15V (+1.25%)

+3.3V as well as +12V start very high with +2.7% and +3.1% over the desired value, though this isn't necessarily "bad". +5V starts lower, but there is not much room for the typical drop. Even at 110% overload all rails are still within specification, and +12V never drops below 12.15V, which is nice (particularly if you're pushing an overclock).

Ripple and Noise

+3.3V ripple quality
Load	Ripple and noise
10%	14.10mV
20%	14.40mV
50%	20.80mV
80%	21.30mV
100%	27.90mV
110%	30.60mV

 

+5V ripple quality
Load	Ripple and noise
10%	10.60mV
20%	16.10mV
50%	19.70mV
80%	27.10mV
100%	34.80mV
110%	40.90mV

 

+12V ripple quality
Load	Ripple and noise
10%	23.30mV
20%	31.60mV
50%	34.40mV
80%	40.20mV
100%	55.80mV
110%	76.10mV

While the voltage regulation was good, the ripple and noise doesn't fare as well. 40.60mV is close to the 50mV limit on +5V; 76.10mV at +12V is okay but still worse than many other power supplies. The 30mV result on 3.3V is also near the limit. All are still within specification, but there's nothing particularly exceptional here; this is just average performance from any decent PSU.

OCZ Noise Levels and Efficiency

Sound Pressure Level
Load	dB(A)
10%	18
20%	19
50%	20
80%	24
100%	26
110%	26

Its nice to see that the OCZ Fatal1ty 550W is silent at low loads. Even at 50% you can't hear anything, provided there is a thick-walled case between the PSU and your ear. You'll definetly hear the PSU at full load, but the noise level is still tolerable. Nice work here!

Efficiency and PFC

230VAC, 50Hz
Load	Efficiency	PFC
10%	73%	0.840
20%	83%	0.877
50%	85%	0.930
80%	84%	0.952
100%	82%	0.958
110%	82%	0.962

 

115VAC, 60Hz
Load	Efficiency	PFC
10%	71%	0.941
20%	81%	0.949
50%	84%	0.976
80%	83%	0.983
100%	82%	0.985
110%	81%	0.986

Now we see why the OCZ Fatal1ty lacks the 80 Plus Bronze certification. The efficiency is always below 84% at 115VAC and very bad at 10% load. OCZ would definitely benefit from an improved design, though with gaming PCs we can pretty much guarantee that you'll be idling at closer to 20% load so it's not a huge concern for the target market. Anyhow, the power factor is good and reaches more than 0.960 on both power grids.

Overall, the OCZ Fatal1ty delivers decent voltage regulation, a nice power factor, reasonable efficiency, and low noise levels; unfortunately, there's a high amount of ripple and the efficiency could be better. Considering these results the OCZ Fatak1ty 550W is just one among many PSUs vying for your dollar. If you can find it on sale for around $50, it becomes a better proposition—and that's exactly what you get if you go with Newegg and their $15 mail-in rebate, but we'd prefer a $50 price without the hassle of an MIR.

Antec TruePower New TP-550

The Antec TruePower New (who puts "New" in a product name?) takes some cues form the EarthWatts line, as Antec uses no polystyrene for the packaging. You get a power cable, four screws, and a user manual. Instead of a cable bag for the modular cables, Antec provides a plastic jacket.  The PSU is RoHS and SLI-ready and comes with an 80 Plus Bronze certification. The cable sleeving is rather cheaply done, but it's better than nothing.

The surface of the TruePower New is very robust. There are quadratic ventilation holes and a small power switch near the power plug. The fan grill does not stick out, and the housing has a length of 15cm.

Cables and Connectors
Fixed/Modular	Main	24-pin 50cm
	ATX12V/EPS12V	8-pin 65cm / 4-pin 55cm
	PCIe	6/8-pin 55cm / 6-pin 55cm
	Peripheral	3x PATA 55-85cm / 3x PATA 55-85cm / 3x PATA 50-80cm+ Floppy 15cm
		3x SATA 55-85cm / 3x SATA 55-85cm / 3x SATA 50-80cm

Antec has more cables and connectors than the other contenders. The problem is that you can't plug in all of the harnesses, as two peripheral harnesses will be left over. However, 55cm long PCIe connectors are nice and 50cm for the 24-pin cable is good as well. Already we begin to see the difference between the TP-550 and the lower priced alternatives.

Since Antec is using a Seasonic design, they had the option to use a Sanyo Denki or ADDA fan. This is a mainstream product so they're using an ADDA fan. It's a ball-bearing type fan with seven blades.

Antec TruePower New Internals

As promised all the caps come from Japan (Nippon Chemi-Con), even if the main cap is just an 85°C @ 2000h device. The EMI filtering is large and includes an MOV. There are shrink tubings on all the wires and the soldering quality is adequate if not great.

The design looks like a Seasonic M12 plus the DC-to-DC PCB from the M12D. DC-to-DC is the reason there is so much power on the +12V rails, since they feed the smaller ones. Remember that Antec is using a PWM-fan, so you can see four small wires on the right side.

Antec Voltage Regulation and Quality

+3.3V regulation
Load	Voltage
10%	3.41V (+3.33%)
20%	3.41V (+3.33%)
50%	3.39V (+2.73%)
80%	3.37V (+2.12%)
100%	3.36V (+1.81%)
110%	3.36V (+1.81%)

 

+5V regulation
Load	Voltage
10%	5.16V (+3.2%)
20%	5.15V (+3.0%)
50%	5.13V (+2.60%)
80%	5.10V (+2.00%)
100%	5.09V (+1.8%)
110%	5.08V (+1.6%)

 

+12V regulation
Load	Voltage best/worst
10%	12.18V (+1.50%) / 12.17V (+1.42%)
20%	12.17V (+1.42%) / 12.16V (+1.33%)
50%	12.12V (+1.00%) / 12.10V (+0.83%)
80%	12.08V (+0.66%) / 12.05V (+0.42%)
100%	12.05V (+0.42%) / 12.01V (+0.08%)
110%	12.03V (+0.25%) / 12.00V (+0.00%)

All +12V show almost the same performance and still stay above 12.00V at 110% load.+3.3V starts very high and reaches 3.36V at full load. The same goes for the +5V rail, which starts with +3.2% and ends at +1.6%.

Ripple and Noise

+3.3V ripple quality
Load	ripple and noise
10%	4.70mV
20%	5.50mV
50%	7.20mV
80%	9.30mV
100%	9.70mV
110%	10.90mV

 

+5V ripple quality
Load	ripple and noise
10%	7.30mV
20%	8.00mV
50%	9.30mV
80%	10.80mV
100%	13.30mV
110%	15.20mV

 

+12V ripple quality
Load	ripple and noise
10%	7.90mV
20%	10.10mV
50%	13.80mV
80%	19.60mV
100%	21.30mV
110%	33.70mV

Holy moly! All of the rails have no remarkable transients and ripple is always below 50% of the allowed level. +3.3V only just exceeds 10mV (at 110%), which is impressive. Overall, these are exceptional results and deserve praise; we wish every manufacturer would do as well!

Antec Noise Levels and Efficiency

Sound Pressure Level
Load	dB(A)
10%	18
20%	18
50%	20
80%	23
100%	27
110%	32

At high loads, Antec is louder than OCZ, but they are very similar overall. When you play games (one of the few times you would be likely to come anywhere near the 550W output), the noise isn't that important anyway, as the GPU/CPU fans are also more audible. The silence at low loads is crucial, and both the OCZ and Antec units do well.

Efficiency and PFC

230VAC, 50Hz
Load	Efficiency	PFC
10%	78%	0.852
20%	84%	0.907
50%	88%	0.933
80%	87%	0.948
100%	86%	0.956
110%	85%	0.958

 

115VAC, 60Hz
Load	Efficiency	PFC
10%	78%	0.957
20%	84%	0.973
50%	86%	0.988
80%	84%	0.989
100%	83%	0.995
110%	82%	0.993

As expected, the Antec is more efficient than OCZ, and the Techsolo is well behind the pace set by 80 Plus. The efficiency and power factor could still be better at low load (for example, Seasonic achieved more than 80% at 10% load), but both are good enough for 80 Plus Bronze and there's not much to complain about.

You Get what You Pay for!

Perhaps our conclusion should also include the warning: caveat emptor (let the buyer beware), because it's clear that some PSUs should never see retail shelves. The Techsolo Black Mamba 550W belongs in this classification if you want a 550W PSU; in fact, the Techsolo is a ~250 watts power supply without an acurate working power factor correction—not to mention the fact that the efficiency is always below 75%.

If you just need a cheap power supply that will function at loads under 250W, perhaps budget products will fit the bill, but we'd suggest looking elsewhere as long-term power costs (and the risk of damaged components) makes this a gamble at best. In our case, the PSU died at 50% load, and there are no real safety functions—not even an MOV in the entrance. Both main switches are undersized and exploded. The protective ground wire is connected to a mounting screw of the main PCB. Again: Bad idea!

While the product looks decent, Techsolo offers nothing more than a few cables ties, one PCIe connector, and very short cables (40-45cm for the main cables). The cable sleeving is a nice extra, but we'd rather have the cost put elsewhere. Nothing else even suggests that this is a quality power supply. The noise for example is always over 22dBA and reached up to 28dBA at "50%" load. Another problem is the noisy PFC-choke, which is really loud and emits a high-pitched squeal. Passive PFC is always a noisemaker. In any case, Antec and OCZ are quieter and better, so just give this one a pass if you happen to be in Europe.

The OCZ Fatal1ty 550W is no superhero on the market, failing to stand out from the crowd. Your system won't run faster, and we have to wonder how much Fatal1ty gets paid for the use of his name—and if it even helps with increased sales, considering he's been quiet of late. This is a minor upgrade of the older OCZ ModXStream Pro 500W, with slightly improved internal devices, but that's about it. The EMI filtering has most necessary components, excluding an MOV. OCZ has switched to Teapo (LH, SC), after the Chinese caps weren't helpful for their public image. We can't say that they have the best characteristics, but they do a good job in power supplies. Now there are more protective foils against short circuits as well. This progress is absolutely welcome.

The downside of the PSU is that the ripple and noise results are very high for an "actual" product. More than 70mV on +12V and about 41mV on +5V can be measured. The efficieny is low at 10% load and not to remarkable at 50% load. Otherwise the voltage regulation is satisfying (never below -2% on all rails) and the power factor is high (above 0.840). The 45cm 24-pin cable should be long enough for small and mid-size cases, while the 4-pin and 4+4-pin ATX12V cables for the CPU could be much longer; we wouldn't recommend this PSU for use in cases where the PSU is at the bottom. Six SATA and HDD connectors are provided and there is a floppy connector at 90cm. The red cable sleeving is cheap but at least it's something.

What about the noise level? It's not bad at all. At low load there is no more than 18-19dBA. Even at full load the fan stays below 30dBA. Overall it is as quiet as the Antec TruePower New, but takes a small lead at high loads. This isn't a bad power supply, and it's reasonably efficient, but the high amount of ripple on the various rails is a concern for long-term stability, particularly if you're actually running this on a higher performance gaming system. Outside of noise levels the Antec is a far better PSU; you just have to decide if it's worth the additional cost.

When we look at the Antec TruePower New 550W, we can see good capacitors (Nippon Chemi-Con), many components for filtering in the entrance including an MOV, and well dimensioned +12V rails. The TruePower New has 55cm connectors for graphics cards and a 50cm 24-pin cable. The cable sleeving is again done rather cheaply, but the number of peripheral connectors gives no occasion for criticism. There is only one real problem: with a limited number of plugs you can't connect all the modular cables—even though this 550W unit should easily be able to handle such a configuration.

As for performance and quality, all the results from our tests are very impressive. The voltage is always over or near the ideal value and there is hardly any ripple and noise on any of the rails: less than 35mV on +12V, and less than 20mV on +3.3V and +5V. Up to 87% efficiency and a high power factor (above 0.850) is the primary reason for the cost; such results can only be reached with high quality devices, and those devices cost more than lesser offerings. In every case, Antec performs better than the OCZ and comes out the clear leader of this trio. And if you've ever wondered what the difference is between "budget" power supplies like the Techsolo and quality offerings like the Antec, hopefully we've managed to shed some light on the discussion.

So what's the overall conclusion? The gap between OCZ and Antec is far shorter than the gulf between OCZ and Techsolo, but you can definitely see why the Antec costs more. Long-term, the increased efficiency of the OCZ will easily pay for itself relative to a budget PSU, though we can't say the same for the Antec vs. OCZ. However, the Antec has much better characteristics elsewhere, and high ripple can put extra stress on your PC's components making the Antec a better choice for enthusiasts and anyone looking for maximum reliability. Is it worth the added cost? That's up to you, but we'd recommend spending as much on your PSU as you can afford; there's no reason to pair quality components (i.e. your motherboard, CPU, RAM, GPU, and SSD) with substandard power supplies. As our results here show, you clearly get what you pay for—though we'd recommend reading reviews to help choose between similarly priced, similarly specced PSUs.