The SilverStone Strider Plus SST-ST1000-P is aimed at the casual user up to enthusiast gamers. It can deliver power to a range of system components that includes mid- to high-end PCI Express graphics cards.

Under our lab testing, the Strider Plus achieved 100 per cent of the manufacturer's claimed performance based on real-world scenarios involving the most commonly used 12 volt rail.

In terms of total efficiency, the Strider Plus lagged behind the other high-range power supplies, such as the Antec TruePower Quattro 1200 and the Nexus RX-1.1K Gold.

However, if you wanted to drag a compliment from us we'd say it performed satisfactory in terms of standby efficiency, achieving the average in this class.

As a PSU topping 1,000 watts, it also produced less decibel noise compared to similar power supplies such as the Antec and the Nexus units, being one of the quietest in its class. Despite the low-noise levels the fan did a good job venting heat, and even the cables did not significantly heat up during high loads.

Despite these good points, vitally, the tested rails exceeded the ATX-specified tolerances, falling outside the standard. The SilverStone Strider Plus SST-ST1000-P also produced a fair amount of jitter at a 75 per cent voltage load.

In a master class of understatement, the PSU has one of the most minimalist black casings we've seen, with only the 135mm fan being of note, generally larger than even the Corsair Professional Series Gold AX1200W. The rear of the power supply is the standard honeycomb grate, used as an exhaust to vent excess heat.

The build quality of the SilverStone Strider Plus is generally good. It is of a standard design with dimensions of 160x85x150mm. Despite this, the Strider Plus is a fat fella, weighing in at a hefty 3.064kg. The manufacturers' stated AC power input is 100-240v 12A-6A 60-50Hz.

The SilverStone unit comes with a total of 23 output connectors; 1x ATX 20/24-pin connector, 2x ATX 8-pin connector, 4x PCI Express 6/8-pin connectors, 2x PCI Express 6-pin connectors, 6x SATA connectors, 6x 4-pin peripheral (MOLEX) connectors, and 2x floppy connectors.

In terms of overall performance the Strider Plus was a disappointment, not performing as well as the other PSUs in its class. The unit could further benefit by improving total power efficiency and reducing the voltage noise.

The Xigmatek 600W PSU is well suited to eco-enthusiasts, with an 85 per cent efficiency rating claimed by the manufacturer, and recycled packaging to boot. In general, home users and casual gamers will benefit by using this PSU. It can certainly deliver power to a wide range of system components, including lower-end PCI Express graphics cards.

Under our testing, the Xigmatek 600W achieved 100 per cent of the manufacturer's claimed performance based on real-world scenarios involving the most commonly used 12 volt rails. In terms of total efficiency, the Xigmatek 600W came in at a very respectable third place, behind other entry-level power supplies such as the OCZ StealthXStream 2 600W and the Antec TruePower 550W.

It also performed moderately well in terms of standby efficiency; coming in around the middle of the field compared to its rivals.

Even under load the PSU produced less decibel noise than all similar power supplies in its class, including the Fractal Design Tesla 650W and the Spire Blackmoon 650W, making it the quietest under test. The large 140mm fan did a good job venting heat, helping to keep the inside of the PC cooler than the outside exhaust, and the cables didn't significantly heat up during high electrical loads.

We were glad to see the tested rails were all within the ATX-specified tolerances, comfortably meeting the standard. The Xigmatek 600W also went on to produce an almost completely jitter free voltage reading at the 75 per cent load mark, forming a near flat line to demonstrate low electrical interference.

The build quality is generally sound and satisfactory, if nothing stellar. It's of a standard design with the dimensions of 160 x 86 x 150mm.

The Xigmatek is a fairly heavy power supply for this size, weighing in at 2.140kg. The Xigmatec 600W has two 12v rails to split loads and the manufacturer's stated AC power input is 100-240V 10A 47-63Hz.

It also comes with a decent – for this class – total of 23 output connectors; 1x ATX 20/24-pin connector, 2x CPU 4+4-pin connectors, 2x PCI Express 6/8-pin connectors, 2x PCI Express 6-pin connectors, 8x SATA connectors, 7x 4-pin peripheral (MOLEX) connectors, and 1x floppy connector.

In general, this entry-level power supply met or exceeded our expectations; the main area of potential improvement is standby efficiency compared to the rest.

The Spire Blackmoon 650W is a PSU that lends itself to systems for power-hungry desktop and mainstream gamers. It'll happily power a range of system components that include mid-range PCI-E graphics cards and SATA equipment and ships with two 12 volt rails as standard.

During all of our testing the Spire Blackmoon 650W achieved 100 per cent of the manufacturer's performance claims, based on real-world scenarios.

However the total efficiency for the Blackmoon lagged behind all the other low-end power supplies under test, including the Xigmatek NRP 600W and the Fractal Design Tesla 650W. It also failed to gain any ground in terms of standby efficiency, and was the lowest performer in its range.

Compounding this poor power performance, the PSU was the loudest product under test in terms of decibel noise when compared to similar power supplies like the SilverStone Strider Plus and the Corsair HX 650W.

The 120mm fan did do its job well, venting heat and keeping the computer cooler on the inside than the outside exhaust point, and the cables did not significantly heat up during the high load tests.

Under load, the tested rails were all comfortably within the ATX-specified tolerances, easily meeting the standard, and the Blackmoon produced an almost jitter free voltage readout at the 75 per cent load mark, creating a near flat line to indicate low electrical interference.

A robust and solid build does help boost our confidence in the Spire Blackmoon 650W and the addition of the blue illuminated translucent fan was a welcome design addition to the otherwise plain black chassis with the usual honeycomb exhaust grill.

Dimension-wise, it's a standard 140 x 85 x 150mm and is somewhat more meaty than similar units weighing in at 2.432kg.

The manufacturer's stated AC power input is 200-240V 50-60Hz 8A and the Blackmoon 650W comes with a total of 16 well selected fixed output connectors; 1x ATX 20/24-pin connector, 1x ATX 8-pin connector, 2x PCI Express 6/8-pin connectors, 4x SATA connectors, 6x 4-pin peripheral (MOLEX) connectors, and 2x floppy connectors.

Despite its SLI-ready capabilities this is really an entry-level PSU providing no modular plugs, and it lags the other PSUs in the test for efficiency and audible noise.

For anyone looking to put a high-quality PSU at the heart of their next desktop PC or mid-ranged gaming rig, the Scythe Stronger 700W wouldn't be a bad choice. It's able to deliver power to a range of system components that include PCI-E and SATA based equipment.

For all of our tests the Scythe Stronger 700W achieved 100 per cent of the manufacturer's claimed performance based on real-world scenarios involving the most commonly used 12 volt rails.

Looking at total efficiency, the Scythe Stronger 700W achieved an average performance in its field of five competitors, placing it in front of other mid-range power supplies such as the NesteQ Xzero 700W, and behind better units like the Cooler Master Silent Pro Gold 800W.

Its main weakness turned out to be standby efficiency, where it trailed most of the field and turned out to be one of the lower performers in its range. Countering this, the PSU produced less decibel noise compared to all similar power supplies in its class, with the sole exception of the Cooler Master Silent Pro Gold 800W, making it among the quietest under test.

The large 140mm fan performed well to vent produced heat, helping to keep the PC cooler on the inside than at the exhaust outlet, and the cabling did not significantly heat up during high load test runs.

During loading the tested rails were all within the ATX specified tolerances, easily achieving the standard. To back this quality up the Scythe Stronger 700W produced a nearly jitter free voltage reading at a 75 per cent load test, making a near flat line to indicate low electrical interference.

The PSU has a simple and effective design consisting of a black casing and fan housing. At the rear of the power supply is a honeycomb grate, used as an exhaust to prevent heat retention. The build quality of the Scythe Stronger 700W is generally good, with a particularly robust feel to it.

It's of a standard design and has dimensions of 160 x 86 x 150mm, and this is largely why the Scythe Stronger 700W has an average weight, measuring in at the 2.024kg mark.

The manufacturer's stated AC power input is 100-240V 12-6a 60-50 Hz. The Stronger comes with a reasonable total of 28 output connectors; 1x ATX 20/24-pin connector, 1x ATX 8-pin connector, 4x PCI Express 6/8-pin connectors, 10x SATA Connectors, 8x 4-pin peripheral (MOLEX) connectors, 2x floppy connectors and 2x intelligent fan connectors.

For a lower-end PSU it put in a strong performance across the board, although it could further benefit by an improvement in standby efficiency.

The Corsair Professional Series Gold AX1200 is ideal for any high-end gamer or those who simply want to power a vast array of high-end hardware, because it will happily deliver power to a range of system components including the most demanding high-performance PCI Express graphics cards.

Under testing, the Corsair AX1200 achieved 100 per cent of the manufacturer's claimed performance based on real-world scenarios involving the most commonly used 12 volt rail.

In terms of total efficiency, the Corsair Professional Series Gold AX1200 performed top of its class, beating all other units tested such as the Antec TruePower Quattro 1200 in pretty much all areas.

Just to start, the standby efficiency was outstanding, being one of the best performers in this highest-end class. One of the few weaknesses we noted was the slightly elevated decibel noise levels when compared to the best power supplies such as the Thermaltake Toughpower 1500W, which was quieter overall.

Thankfully for Corsair, that additional noise was justified because the fan performed excellently, helping to cool the PC efficiently. Reassuringly, the supplied power cables did not significantly heat up during high loads.

Importantly, the tested rails were all within the ATX-specified tolerances and the Corsair Professional Series Gold AX1200 produced an almost jitter free voltage reading at a 75 per cent load, making a near flat line showing less electrical interference.

For its design, Corsair has taken a minimalistic approach with the PSU, using a plain black casing complimented by a black fan. At the rear of the power supply is a honeycomb grate, used as an exhaust to vent excess heat. The build quality of the Corsair Professional Series Gold AX1200 is of a reassuringly high standard.

Physically, the PSU is larger than a standard sized unit with dimensions of 210 x 86 x 150mm. Despite this, the Corsair Professional Series Gold AX1200 is not as heavy as you'd expect, weighing in at 2.138kg.

The manufacturer's stated AC power input is 100-240V 15A 50-60Hz. If you were in any doubt about the premium-level packaging for this unit the Corsair Professional Series Gold AX1200 comes with a staggering total of 39 output connectors; 1x ATX 20/24-pin connector, 2x EPS/ATX 4/8-pin connector, 6x PCI Express 6/8-Pin connectors,16x SATA Connectors, 12x 4-pin peripheral (MOLEX) connectors and 2x floppy connectors.

Without doubt, Corsair has put together a stunning PSU that performs extremely well in most areas. With an impressive total power efficiency, it's only flaw is a slightly louder noise level for its class.

Aimed at power-hungry desktop users and the more ambitious gamer the Antec TruePower 550W can deliver power to a range of system components that include dual GPUs and dual/quad-core CPUs from its four 12 volt rails.

Rather impressively in regards to total efficiency, the Antec TruePower 550W led the field, beating out other lower-range power supplies in its class, including the Xigmatek NRP 600W and the OCZ StealthXStream 2 600W.

It also achieved a very respectable third place out of seven contenders in terms of standby efficiency, narrowly losing out to the OCZ StealthXStream 2 600W and the Corsair HX 650W.

This PSU produced slightly more decibel noise compared to similar power supplies in its class like that Xigmatek PSU and the Fractal Design Tesla 650W, although it was still among the quietest under test. The 120mm fan performed well to vent heat and the cables remained fairly cold during high load testing.

Throughout all the testing the Antec TruePower 550W achieved 100 per cent of the manufacturer's claimed performance over its 12 volt rails. These tested rails were all within the ATX-specified tolerances, successfully adhering to the standard.

The TruePower produced the least amount of jitter voltage of all similar power supplies under test at the 75 per cent load level, making an almost perfect flat line translating to very-low electrical interference for the end user.

The PSU has a black casing, complimented by a square patterned grate at the rear, used as an exhaust to vent excess heat. The build quality of the Antec TruePower 550W is generally robust. It is of a standard design and has dimensions of 150 x 86 x 150mm and weighs in at an average 2.135kg.

The manufacturers' stated AC power input is 100-240V 8A -4A 50-60Hz. It comes with a total of 24 well selected output connectors; 1x ATX 24-pin connector, 1x CPU 8-pin connector, 1x ATX 4-pin connector, 1x PCI Express 6/8-pin connector, 1x PCI Express 6-pin connector, 9x SATA connectors, 9x 4-pin peripheral (MOLEX) connectors, and 1x floppy connectors.

A well-engineered PSU with very good overall performance; it leaves little in regards to improvements for its class and met the manufacturer's specifications for 100 per cent of its loads.

The SilverStone Strider Essential Series 500W is particularly suited to standard desktop users and casual gamers. It can deliver power to a range of system components that include mid-ranged PCI Express graphics cards.

Under load, the SilverStone Strider Essential Series 500W ST50F-ES achieved 100 per cent of the manufacturer's claimed performance based on real-world scenarios involving the most commonly used 12 volt rails.

In terms of total efficiency, the SilverStone Strider Essential Series 500W ST50F-ES lagged slightly behind other lower-range power supplies like the Xigmatek NRPPC602 600W and the Antec TruePower 550W. However, it gained significant ground in terms of standby efficiency, and was one of the best performers on test.

Another big win for this PSU was the low decibel noise compared to similar power supplies, such as the OCZ StealthXStream 2 600W and the Corsair HX 650W, with it being among the quietest under test.

Its 120mm fan performed well venting heat, helping to keep the PC cooler on the inside, and the cables did not significantly heat up during high loads.

We were also impressed that the rails were all within the ATX-specified tolerances and that the SilverStone Strider Essential Series 500W ST50F-ES produced an almost jitter free voltage reading at 75 per cent load, making a near flat line to show minimal electrical interference.

For what is effectively a budget PSU, we can excuse its basic black casing, complimented by a black fan and the standard rear honeycomb grate, used as an exhaust to vent excess heat. The build quality of the 500W Strider is generally good.

It's a standard design with dimensions of 140 x 85 x 150mm and the SilverStone PSU comes in at a lightweight 1.474kg. The manufacturers' stated AC power input is 115-230 v 6.5A 60 Hz.

The SilverStone Strider Essential Series 500W only comes with a basic total of 12 output connectors; 1x ATX 20/24-pin connector, 1x CPU 8-pin connector, 1x PCI Express 6/8-pin connector, 1x PCI Express 6-pin connector, 4x SATA connectors, 3x 4-pin peripheral (MOLEX) connectors, and 1x floppy connector.

Overall, this PSU performed extremely well. It could further benefit by improving total power efficiency but it matched the manufacturer's specifications for 100 per cent of the load tests and produced minimal electrical noise.

The Nexus RX-1.1K Gold is aimed squarely at gamers and those with a number of power-hungry components. Its meaty 1,100w output can deliver power to a range of system components that include, of course, the most thirsty top-end PCI Express graphics cards.

In specific tests, the Nexus RX-1.1K Gold achieved 100 per cent of the manufacturer's claimed performance based on real-world scenarios involving the most commonly used 12 volt rail.

In terms of total efficiency, the Nexus RX-1.1K Gold gave an average performance in its class, falling slightly behind other higher-ranged power supplies like the Antec TruePower Quattro 1200 and the Thermaltake Toughpower 1,500W. However, it gained significant ground in terms of standby efficiency since it was one of the best performers in its class.

Despite the high power rating, the large 135mm fan helped the unit produce less decibel noise compared to similar power supplies in its class, though it was no match for the Thermaltake 1,500W PSU.

That large fan also did a good job venting heat, helping to keep the PC cooler on the inside; however the output cables were quite hot to the touch at high load intervals.

We noted a fair amount of jitter with the Nexus RX-1.1K at a 75 per cent voltage load, but this was still not as dramatic as the SilverStone Strider Plus.

Nexus has attempted to inject a little personality the cables use a snakeskin-effect patterned mesh and the unit itself has a classy titanium coloured finish that's smooth to the touch, though the rear exhaust uses a standard honeycomb grate.

In general, the built quality of the Nexus RX-1.1K Gold leaves us without any complaints.

As with many of these high-end units, the chassis is larger than average with dimensions of 165x85x150mm. The Nexus RX-1.1K Gold is fairly light considering its extra length and with the amount of power on offer, weighing in at 2.239kg.

The manufacturers' stated AC power input is 115/240V 15A/7.5A 47/63Hz. The Nexus RX-1.1K Gold comes with a substantial 30 output connectors; 1x ATX 20/24-pin connector, 1x ATX 8-pin connector, 1x ATX 4/8-pin connector, 6x PCI Express 6/8-Pin connectors, 9x SATA Connectors,10x 4-pin peripheral (MOLEX) connectors and 2x floppy connector .

Despite its excellent standby efficient the unit is a disappointment in terms of its overall performance, it simply can't stand up to the other PSUs in its class and really needs to improve its total power efficiency.

The OCZ StealthXStream2 600W is aimed at those of us with mainstream systems and modest gaming needs, but that still desire a quality power supply. It'll happily delivers power to multiple system components that include PCI-E graphics cards and SATA devices from four 12 volt rails as standard.

Under loading total efficiency for the OCZ StealthXStream2 600W put it second out of seven similarly classed power supplies, only losing out to the Antec TruePower 550W by the narrowest of margins.

However, it beat all competitors in the standby efficiency stakes, finishing an impressive first in its class.

Despite its 120mm fan, this PSU came in at the mid-range mark on decibel noise, when compared to similar power supplies like the Spire Blackmoon 650W at the louder end and the Xigmatek NRP 600W on the quieter side.

The fan – aided by additional air outlets on the supply – vented heat well, helping to keep the PC cooler on the inside than at the exhaust, and the PSU cables did not significantly heat up during the highest load tests.

In specific tests, the OCZ StealthXStream2 600W successfully met 100 per cent of the manufacturer's claimed performance figures, based on real-world scenarios for its 12 volt rails.

The tested rails were also all within the ATX specified tolerances and happily conformed to the standard. The OCZ StealthXStream2 600W produced an almost flat line on voltage noise at a 75 per cent load test, making it virtually jitter free, helping to provide a low level of electrical interference.

We found the build quality of the OCZ StealthXStream2 600W to be pleasingly generally robust, despite its uninspiring black casing and an internal black fan. It has bog-standard dimensions of 140 x 86 x 150mm, while the weight of the OCZ Stealth XStream2 600W is just 1.863kg. The manufacturers' stated AC power input is 100-240 V 9.5-4.5A 50-60Hz.

The OCZ Stealth XStream2 600W ships with 13 well selected output connectors; 1x ATX 20/24-pin connector, 1x CPU 4+4-pin connector, 1x PCI Express 6/8-pin connector, 1x PCI Express 6-pin connector, 3x SATA connectors, 5x 4-pin peripheral (MOLEX) connectors, and 1x floppy connector.

For a low-end power supply, the power performance was excellent. It could do with improvements to its noise levels, and an extra PCIe connector would definitely please us.

On the face of it the Corsair HX 650W is particularly suited to standard desktop systems and casual gaming machines. It provides power to a range of system components that include PCI-E and SATA devices. It comes with a robust single 12 volt rail is 80Plus Bronze certified, Nvidia SLI compliant, and is semi-modular.

Under our tests, the Corsair HX 650W achieved 100 per cent of the manufacturer's claimed performance based on real-world scenarios involving the most commonly used 12 volt rails.

Looking at total efficiency, the Corsair HX 650W came in around the mid-range mark for its class, lagging behind other power supplies such as the Antec TruePower 550W but still ahead of others like the Spire Blackmoon 650W.

It did gain substantial ground in terms of standby efficiency; achieving second place from a field of seven similar power supplies. This PSU produced a fraction more decibel noise when compared to most other PSUs in its class like the OCZ StealthXStream 2 600W and the Xigmatek NRPPC602 600W, although the overall noise difference was minor.

Thankfully, the tiny bit of extra noise was justified because the 120mm fan performed well to vent heat, helping to keep the PC cooler on the inside than it was at the exhaust, and the cables did not significantly heat up during high loads.

The tested rails were all within the ATX specified tolerances, comfortably meeting the standard. Importantly the Corsair HX 650W did not suffer from high electrical interference, in fact it produced an almost jitter free voltage noise reading at the 75 per cent load level, translating to a near flat line on the corresponding oscilloscope printout.

Despite the price, the PSU has a mostly plain-black casing, complimented by a somewhat dull powdered blue logo and the standard honeycomb-style exhaust mesh. The build quality of the Corsair HX 650W is generally robust with a professional finish.

It's a standard design and has dimensions of 150 x 85 x 150mm and weighs in at 2.271kg, which is pretty heavy for this class of PSU. The manufacturer's stated AC power input is 100-240v 10A 50-60Hz.

The Corsair HX 650W ships with a total of 25 output connectors; 1x ATX 20/24-pin connector, 1x EPS/ATX 4/8-pin connector, 4x PCI Express 6/8-pin connectors, 9x SATA connectors, 8x 4-pin peripheral (MOLEX) connectors, and 2x floppy connectors.

Despite its strong overall performance, the PSU could further benefit by improving total power efficiency, but it did meet the manufacturer's specifications under load testing with a noise-free result.