Silverstone Zeus 560w ST56ZF ATX PSU Page: 1

Only a few weeks ago I took a look at Silverstone's 560w Strider series power supply. In testing this unit faired very well, and actually managed to score a respectable 8/10 in our review.

You would think that Silverstone couldn't do much to improve on this score, however, today I'll be taking a look at their highly acclaimed Zeus series power supply. With the same output rating of 560w, can this unit actually be any better than the Strider?


On removing this unit from its cardboard shipping box, the first thing I noticed was how much bigger the Zeus's box was compared to the Strider. With one box in each hand I could also clearly feel the weight difference between the two boxes. Maybe this is a sign of some extra quality components inside the Zeus? We'll soon find out!

Zeus 560w Box Zeus 560w Box

The ST56ZF follows the same packaging design as all previous power supplies from Silverstone, and many of their other products. The packaging gives plenty of information regarding the power supplies specification as we can see above.

Most interesting of all features listed on the top of the box is that the Zeus ST56ZF actually has only a single +12v rail. This is indeed a surprise, considering that the Strider 560w featured 2x +12v rails.

No mention of efficiency nor noise (dBA) ratings has been made on the packaging, which may be slightly worrying for those of us who enjoy silence or want to keep our energy bills low - but we'll find out for sure later on in the review.

Zeus 560w Box Zeus 560w Box

Flip around to the other sides of the packaging, and we can see that Silverstone have included some information regarding the rail layout, incorporated protection features and the power supplies supported standards (EPS, SSI..).

Zeus 560w Box Zeus 560w Package

Included in the box are the following items:

- ST56ZF Manual
- Power Cord
- 4x ATX Screw
- 1x EPS12v to ATX12v (8pin-4pin) Converter
- 1x Power Supply
- PSU Mounting Rail

As with our previously reviewed 750w Zeus power supply, the ST56ZF is very well packaged. The unit is protected by a two styrofoam layers that cover all corners of the PSU. Also included is a small cardboard box containing the power cord, screws, cable ties, Mounting rail and an 8-pin to 4-pin PV-12v converter.

The bundle of cables are contained within a bubble-wrap sleeve and tied together with a large cable-tie.

Silverstone Zeus 560w ST56ZF ATX PSU Page: 2

The following specification has been taken directly from Silverstone's Website.

- Powerful single +12V rail (38A) for special performance requirements
- Dual PCI-E 6pin connector (NVIDIA SLI Certified)
- Four Serial ATA connectors
- Industrial class components
- Support for ATX 12V & EPS 12V
- Active PFC

Zeus 560w Specs

Most notable of the specifications, is the fact that the ST56ZF only has a single +12v rail rated at 38a which is quite rare in modern day power supplies.

However, many people do prefer single railed PSU's as it aliviates some of the problems raised when using high-end graphics cards. The problems generally appear when users attempt to use their multi-railed PSU's in a SLI / Corssfire configuration, only to find out that the rail assigned to providing PCI-E power is simply not able to cope.

Silverstone Zeus 560w ST56ZF ATX PSU Page: 3

Unlike some of the other power supplies I've reviewed recently, the ST56ZF is by all means a standard sized ATX PSU. Measuring 150mm x 86mm x 160mm (HxWxD), the Zeus 560w is actually 10mm longer than its brother the Strider, but should still pose no problems fitting in any ATX case.

Weighing 2.5kg, my initial thoughts about this unit being heavier than the Strider are certainly correct.

Zeus 560w Front Zeus 560w Back

Silverstone Side Zeus 560w Light

My initial impressions on the look of this unit were that it is a bit of an 'ugly duckling'. The power supply is sprayed in matt black paint which is all fine, but the back of the unit sports a 'punched' fan grill, rather than making use of a wire fan grill seen on almost all other power supplies. In my opinion this gives the power supply a "computing in the 80's" kind of look.

The ST56ZF has the ability to auto-detect input voltage and switch between 110v/240v accordingly. This means there is no requirement for a voltage selection switch.

Also present on the back of the unit is an LED which shows you the current status. When switching the Power Supply on the LED turns from Red to Green. Only when the LED is Green is DC power supplied to the rails.

The sides of the unit are pretty much standard, with one side being covered with the Silverstone specification sticker, which contains the usual warnings and info.

Zeus 560w Front

The front of the unit is comprised entirely of a mesh grill, which provides the 80mm fan installed in the back of the unit with a supply of air to pull over the massive heatsinks installed inside the unit.

Silverstone Zeus 560w ST56ZF ATX PSU Page: 4

In past reviews, I've been pleasantly surprised by the number of connectors included with Silverstone power supplies, but disappointed by the lack of sleeving on all cables. Let's see if the Zeus 560w follows the trend.

Zeus 560w Cables Zeus 560w Cables

Zeus 560w Cables Zeus 560w Cables

Yet again, Silverstone have only decided to sleeve the ATX, EPS12v and PCI-E cables leaving the Molex and SATA cables as bare wires. This is a great shame, as Silverstone have done and excellent job on the sleeved cables, using both cable ties and heat shrink to hold the sleeving in place.

Zeus 560w ATX Zeus 560w EPS12v

The ATX connector on the ST56ZF is native 24-pin. However, as you can see above, a small block of 4 connectors can be broken off to switch the connector to 20-pin, and thus make it compatible with older motherboards.

Rather than employing the same idea for the EPS12v connector, Silverstone have decided to provide an extension cable which scales down the connector from an 8-pin EPS12v to a 4-pin ATX12v connector.

Connectors Connectors Connectors

Connectors Connectors Connectors

With 4 SATA and 6 Molex plugs, the ST56ZF should have enough connectors to power the components in most systems without any problems.

Silverstone Zeus 560w ST56ZF ATX PSU Page: 5
Looking Inside

The weight alone is enough to tell me that this is a well built power supply, however let's take a look inside and find out exactly what is making the ST56ZF so much heavier than its brother, the ST56F.

Zeus 560w Insides Zeus 560w Insides

Zeus 560w Insides Zeus 560w Insides

To say that this power supply is 'jam packed' would be a serious underestimate. Every square inch of the casing is occupied by components, all of which are tidily arranged, but didn't leave me with much room to have a poke around inside to see what I could find.

The oversized aluminium heatsinks attribute to a large portion of the weight, with the rest being mostly down to the huge capacitors hiding beneath them.

Zeus 560w Pots Zeus 560w Etasis

Taking a closer look inside we can see that the Zeus 560w possesses an adjustable potentiometer (pot). Pots can be used in most cases to increase the voltage output on a power supplies rails, which can be handy if the outputted voltage drops below what you would consider to be acceptable.

I also noticed that the internals of this power supply are manufactured by a company called Etasis, who are widely know for manufacturing some of the best power supplies in the industry since 1996.

Zeus 560w Fan Zeus 560w Fan

I was pleasantly surprised to see Silverstone using the same Sanyo Denki San Cooler 80mm as installed in their higher-end Zeus 750w PSU we reviewed a few weeks ago. The San Cooler pushes 42cfm at a noise level of 32dBA when running at 12v. This may sound a bit too noisy for some, but we'll see what it's like on the next page.

Silverstone Zeus 560w ST56ZF ATX PSU Page: 6
Load Testing

In order for the results from all current and future PSU reviews to remain fair and comparable, Overclock3D uses a custom built Power Supply load stress tester.

The tester is capable of placing loads on the following rails:


+3.3v - 20a Load
+5.0v - 20a Load
+12v1 - 10a Load
+12v2 - 10a Load
+12v3 - 10a Load
+12v4 - 10a Load
(or 20/40a on a single +12v rail)


The results are collected from a Mastech MAS-345 Multimeter which logs its readings via RS232 to a PC.

Zeus 560w 3.3v Rail Zeus 560w 5v Rail

Zeus 560w 12v Rail

Some very impressive results from the Zeus 560w on all of its 3 rails. Neither rail went anywhere near close to falling outside of ATX specification (+/- 5%), and there was very little fluctuation observed on any of the rails during testing.

What I did find surprising was the similarity between the results of this unit, and the previously reviewed ST56F. I was expecting the Strider series PSU to not fair quite as well as the Zeus, but this is just testament to the high quality components that Silverstone use across their entire PSU range.

Efficiency Testing

Another new addition to the Overclock3D PSU testing procedures is testing the efficiency of the power supply. These results will be helpful for people looking to save money on their electricity bills (or the environment), and will also allow us to see how close manufacturers efficiency ratings are to the truth.

The tests are performed by measuring the wattage consumed by the power supply at the mains against the power (in watts) consumed by the OC3D power supply stress tester.

The results may not be as accurate as those produced by professional testing equipment, but it will certainly come in handy when comparing several power supplies against each other.

Zeus 560w Efficiency

The Zeus 560w was placed under a load of 406 watts. This counts for a total of 72% of the power supplies rated output. At this load, the power supply required 472 watts from the mains to produce the 406 watts required by our custom made power supply tester.

Therefore the efficiency of this power supply can be found by a simple equation: (406 / 472) * 100, which works out to be 86%

Higher loads may reduce the efficiency results of this power supply, but at a load of around 70%, an efficiency rating of 86% is simply excellent for any type of power supply, especially that of one which is able to maintain such stable voltages under load.

Temperature Testing
Quite often, the cooling methods employed by some manufacturers are inadequate, and result in heat from the power supply finding its way back into your case.

The OC3D Temperature Tester involves placing the power supply into a standard ATX case, and measuring temperatures at various places around the power supply after 30 minutes at idle and full load on the OC3D PSU Tester.

Temps Idle Temps Load

Ambient: Room temperature taken approx 10ft away from testing equipment.
In: Temperature taken 5" away from the PSU ventilation grill inside the case.
Out: Temperature taken 5" away from the PSU fan at the back of the case.

Under idle conditions the Zeus 560w only increased the temperature of the case by 1.2°C, which is very respectable for a power supply utilising an 80mm fan.

Under heavy load, the Zeus 560w increased the internal case temperature by 3.3°C whilst managing to push most of the hot air out of the back of the case. This temperature increase should pose very little problems for people with small cases, and no additional case ventilation will be required when operating this power supply.

Noise Testing

As mentioned earlier in the review, the ST56ZF uses the same 80mm fan as its bigger brother the ST75ZF. As a result of this, the noise levels have not changed, and the power supply remains quite loud at idle and load.

It does seem like the installed Sanyo Denki San Cooler is running at full speed regardless of the power supply temperature, which is a great shame, as if a fan controller was installed, this could reduce the noise output significantly.

Silverstone Zeus 560w ST56ZF ATX PSU Page: 7

The Zeus 560w ST56ZF is yet another great power supply from Silverstone. The voltage stability under load was excellent and despite the fact that Silverstone neglected to include the efficiency ratings on the packaging, the ST56ZF actually faired very well in our tests.

All of these excellent attributes are only let down by the noise of the ST56ZF both at idle an under load, which will leave the silent PC builders among us reaching for the earplugs.

Retailing for £86 over at the ST56ZF is slightly more expensive that 560w offerings from other manufacturers. However, with a name like Etasis under the hood, you can be sure that this power supply will serve you well long into the future.

- Stable and powerful rails
- Efficient in our tests
- Internals made by Etasis
- Plenty of connectors
- Adjustable Pots

- Not all rails sleeved
- Not the best looking of PSU's
- Noisy regardless of load.

OC3D Recommended

Thanks to Silverstone for providing this unit for review.

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