Silverstone Zeus ST85ZF 850W Power Supply Review

Cases & PSU/Power Supplies by KeithSuppe @ 2007-01-11

Silverstone Technology Ltd. is a relative newcomer to the PC-world having been founded in 2003. As a manufacturer of power supplies, CPU-coolers and enclosures they aggressively sought to compete with the very best in these product categories. Over the last year they have come into their own with the release of the well received Temjin TJ06 aluminum case and Zeus line of PSUs. Silverstone is now a relatively familiar name and we have the flagship of the Zeus series, the ST85ZF.

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Zeus ST85ZF

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There are many ways to build a power supply, unfortunately for the consumer cost most often dictates design. For years power supplies were little more then inconsequential grey and black boxes to which very little attention was bestowed. Slowly as power demands changed and loads became slightly more complicated a few pioneers such as PCPower & Cooling decided it was time to exemplify what was available when engineers cared about design integrity. It may have been SLI which began the final feeding frenzy, nonetheless by the time CPU's such as Intel’s Dual Core aka Cedar Mill and GPU's such as the NV47 (aka G70) began taxing average PSU's blood was in the water. Just when it seemed as if it couldn't get anymore complicated for the consumer, the ATX/EPS12V Power Supply Guides appeared which were both a curse and blessing for PSU manufactures.

In a sense it was a financial windfall for those manufacturers astute at marketing hyperbole, until you consider all these events ran concurrent with the introduction of the infamous EPS12V Power Supply Design Guide (PDF) and ATX 12V Power Supply Design Guides (PDF). These Byzantine "requirements" imposed on PSU makers were not only defeatist, they were deleterious to the evolution of the PSU. Ironically the same events which forced some of more talented PSU makers to abandon the best design conducive to rising power demands simultaneously introduced power supply design and theory to the masses. With just about every review which discussed a multiple Rail power supply the author found themselves explaining the reasons behind that design. PC Users learned more about that "black box" then ever before.

Still the fundamental flaw in PSU's following said guidelines were that they limited 12V Rail current limit at 18A (22A Peak) and specific Rails had to originate from independent solder points to meet the 240VA safety limits. Luckily the standard were unofficially dropped not long after they were introduced, however; most PSU makers live by specifications, trade marks, logos, standards etc, and they’re not willing to forfeit that "compliance" sticker on their box. As an R&D leader PCPower & Cooling has been a detractor of several aspects of the guidelines mentioned and led the way back to the single rail model with the introduction of their 1000W single rail 1KW-SR.

While there is gradual momentum toward a new single rail design, for the most part the industry is still building and/or selling multiple 12V Rail power supplies, especially to Gamers whom should run from those designs. And while the events above hamstrung PSU makers, some manufacturers made great strides designing by necessity. As a newcomer Silverstone wasn't mired down in repetition or complacency and this is evident in their Zeus ST85ZF which we test today. Silverstone has also released a 1KW single rail model, the Olympia OP 1000 offering 80A (88A Peak) on the 12V Rail. We hope to test this unit soon as well.

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Specifications from manufacturers website

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Packaging can reveal a lot about a product. Does the manufacturer spend too much or too little on packaging, are the graphics phenomenal, yet the components are left to rattle around inside? Of course spending a half page from the moment the package arrives in various stages of "undress" is a waste of bandwidth. Of primary concern should be how the manufacturer "packs" the product so it remains safe during shipping, this only requires one photo.

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Silverstone used foam bracing to prevent the product from shifting during its lengthy travels. While bubble wrap is the packaging of choice based on cost (and there's substantial savings in packaging), it's always better to center-brace an object just in case the box is punctured or dropped.

Onto connectors ->
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Comment from Sidney @ 2007/01/11
From Hardware Secrets; Why 99% of Power Supply Reviews Are Wrong. I'm sure that article will have a substantial impact on most PSU reviews you have read.
I've read the article the day it came out, and found the statement rather inaccurate. A Chroma station, measuring amp and or wattage or voltage by replicating the manufacturer QC station process, and even taking IQC (incoming QC on purchased components) are for the engineering professional in electrical field. When I test drive a car, I only need to know how it responses, sitting/driving position, steering inputs, acceleration (if it is important to me), gas mileage (if it is labled for good mileage consumption), price point and the "look", etc, etc ...... One thing I don't mind not knowing is all the engine, chassis, suspension, gear-box design and specifications (although some of us do want to know because we are very good at it).

99% of reviews are wrong sounded is a bit odd. It depends on the type of audience; 99% are electrical engineers (by formal training or otherwise) and PC enthusiasts; leaving 1% reader who asks that give me a power supply that fits well in my case and support my system without over kill in paying for something I don't need is a strange statement.

By the way, the article serves me well
Comment from EsaT @ 2007/01/19
I just checked article more closely and I think you are wrong about 12V rails being really separate.

Basing to these pics looks much like at least 1 and 2 are "jumpered" (those thick metal jumpers) from same trace.
And basing to bottom side of PCB also 3 and 4 are propably similarly connected.

In fact looks like all 12V rails are directly connected to each other after those "jumpers", PCB traces seem to connect to each others on left edge of pic.

Originally Posted by lazyman View Post
When I test drive a car, I only need to know how it responses...

99% of reviews are wrong sounded is a bit odd.
So you test drive car using just gear 1?
Or more precisely without any driving and seeing just that engine works at idle?
Comment from jmke @ 2007/01/19
rather testing driving the car on race roads, normal roads, traffic jams, long distances, short distances, parking, booth space, easy maintenance, wheel removal kit, seat arrangements, mirror placement, etc etc

you don't need to know how the engine works to make an evaluation of how the car drives

knowing how the engine works can help to explain why the car drives as it does, but it's not a necessary ingredient to make a good evaluation of the car, of course, cars and PSU are not quite a like, and comparo here might not be appropriate
Comment from Sidney @ 2007/01/19
If it is automatic trans; most people don't just put it in "D"; drive away
If it is humming along quietly, most drivers don't care how it works
I am referring to majority of drivers.
Comment from EsaT @ 2007/01/19
Originally Posted by lazyman View Post
I am referring to majority of drivers.
But most people propably wouldn't trust test drive of car done by using only gear 1, that's what that majority of PSU reviews with barely 1/3 of load specified in ads of PSU are...

On the other hand this specie might have once again digged deeper than previously reached level of rock bottom.
Comment from Sidney @ 2007/01/20
You don't buy a car just by reading test report I hope
Comment from jmke @ 2007/01/20
it does help make the decision a lot, testing driving PSU is hard
Comment from Sidney @ 2007/01/20
My initial post was related to the 99% reviews being wrong. Here is my take-
1) A car is rated to have 500HP rear or front wheel power; top speed 180MPH. There will be manufacturing variables, and a dyno test may or may not prove 100% accurate. Now comes the 180mph test, again there are many variables plus having a track to do the test against normal traffic. A test drive reviewed at 120 MPH without the track to top out is not 100% wrong. It merely ran out of track on this part of the review.
2) Since PSU is not regulated by any government (unlike cars) rating except UL for safety. It is highly dependable on the manufacturer's ablility to hold certain professional standards such as ISO which I strongly recommend consumers to look into.
3) The use of any test equipment not regularly certified does not mean much to me.

Lastly, PSU tested even at 100% spec on bench using Chroma station at a given time does not gurantee real life performance against weather condition and irregular or variable input voltage (from the wall or motherboard). Look for solid and reputable manufacturer or name brand; reading test reports include cable length, flexibility, size to fit most or just certain cases, and noise level; to say 99% of reviews are wrong because they might not test the max output is "odd".

We could go another step to look into component specs +/- 3%? Or requesting BOM (bills of material) and supplier listings?
Comment from Liquid3D @ 2007/01/25
I actually re-evaluatewd that article myself. I also found several points which were inconsistent. I wasn't trying so much to discredit our or any other methodologies as I was trying to challange those sites whom feel their tests are beyond reproach. Many of the top test sites with the very best hardware use voltage regulation as a standard test.

When you think of it, since all PSU's have voltage regulation it's not as if their testing the PSU's "power reserve" their actually measuring (if it's possible) the unit's ability to compensate for Rail fluctuation. Without "true" independent voltage regulation fluctuation will be regulated, often at the xpense of theo others Rails. Therefore measuring rail stability may only show one or two phenomenon: First - time it takes to compensate (get the rail back to "spec". Second - wether or not PSU is able to compensate without any affecting other rails or circuits in the design. The paper states the latter is almost impossible because one would need to monitor all rails simultaneously.

IMHO it's not so much the rail in question is immedately regulated, but more importantly this regulation is proprietary as is the current source behind it.

For exmaple if 12V3 dips and it is compensated for, does this now effect 12V1, 12V2 and 12V4? While independent voltage regulation may avoid any impact on other rails, much more important to me is where that power comes from?

The jumpers you refer do not seem to connect any of the 12V rails on the face of it, but I'll follow the traces to be sure if you like?