Sky Hawk Power One 620W PSU Review

Cases & PSU/Power Supplies by KeithSuppe @ 2005-04-24

We take a closer look at SkyHawks 620W PSU; available for less then $100 is it any good? Let us find out.

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Audio Standby Feature and Thermal Fan Control

The most unique and controversial feature of the unit has to be its Audio Standby function. Along with the 24-pin, 4/8-pin motherboard connectors, a non-modular CD-ROM Molex is designed to power a CD drive whenever the unit is plugged in, and its rear power switch is on.

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A supplied IDE (CD-ROM) cable, analog CD cable with splitter to motherboard CD-IN and PCI slot output jack offer a proprietary method for listening to music without powering on your PC. Unfortunately, two problems exist inhibit the proper function of this feature. First this is only for those with stereo (2-channel) sound system or headphone. Second, the splitter audio cable from CD-OUT on the player, to CD-In on motherboard is too short. A simple fix would be lengthening the splitter; a better fix would be a 5.25 or 3.5 front-plates with electronics for 7-channel surround, and a longer audio cable. Regardless if your CD/DVD drive doesn’t have a front panel Play button it's all moot.

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While the feature has been described as a "marketing gimmick" I'm not so sure this is true. I believe SkyHawk engineers may have tried to imitate recent PC features where DVDs can be played without having to boot into the operating system. Whatever the reasoning behind the Audio Standby, it doesn't have an effect on the bottom line.

Power One fans do not run until an internal temp of 40°C is reached and maintained. Seeing the fans motionless my first instinct lead me to think the unit was malfunctioning, until I recalled the 40°C spec which is how virtually silent operation is achieved. When the fans do kick-in the noise level was barely audible. Placing my hand on the rear of the unit prior to fan operation gave me pause for concern as the heat build-up seemed substantial. Given our physical uncomfortably above the 29°C level it's difficult to get our minds around tolerable operational temps for micro-electronics which often hover around 40~100°C depending on the part.

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next we see the Power One installed and running in TTGI USA's aluminum tower case TT-201T3-S.

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Test System
CPU Intel P4 550 Retail-3.4GHz LGA 775
Mainboard Asus P5AD2-E Premium BIOS 1004
System RAM Mushkin DRR2-533MHz PC2-4200 3-2-2-8 1024MB Dual Channel (DIMM 1,3)
Video Sapphire ATI Radeon X800 XT 256MB GDDR3
Power Supply SkyHawk Computer Group Power One GM620SC
H20 Cooling Alphacool Xtreme Pro Set 240 substituite NexXxos XP BOLD S.775
Operating System Windows XP SP2

Test conditions:

I verified voltages inserting the probes from a Fluke-187 digital multi-meter directly into the reverse 24-pin motherboard connector using ExtremeOverclocking's excellent Power Supply Guide. This by far the best guide on the internet providing step by step instructions with photos, it is also the only method I've found to properly monitor the 12v line with a multi-meter. In each case I monitored voltages under IDLE and LOAD using S&M CPU Burn-In to stress the system for a full 20 minutes cycle and several minutes into a second cycle. Voltages were tested at default speed 3.4GHz (17x200FSB) and default vcore 1.38V. Then raising vcore to 1.6V overclocked to 4.2GHz (17x250FSB). The Fluke readings are below, the second chart shows Asus Probe utility results which also includes vcore data.

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SkyHawk Computer Group has provided us with an excellent PSU in spite of its misgivings. Unfortunately its failure to meet the guidelines discussed on the next page, wouldn't make this particular unit the best future investment. I wouldn't recommend it for the upcoming Intel Dual-core Processor, or any AMD FX models. Fortunately the revised edition should offer an outstanding value so long as it meets EPS 2.1 and ATX 2.01 12V split rail guidelines. If the price of the revised units are similar to this unit's cost it's a PS I would certainly look for. Insofar as safety concerns where the 12V rails are at issue, Power Ones currently on store shelves do not meet certain UL Labs specifications for safety in household electrical devices (IEC 60950-1). Contact SkyHawk if you have questions or concerns. Needless to say, you shouldn't expose yourself (touch) to system devices while their powered up, or even plugged in. NO guidelines, no matter how stringent or seemingly fool proof can be as effective as Common Sense.

The fact SkyHawk has now revised these units to meet the aforementioned guidelines speaks volumes for that company. Their doing so in just 30-days is a commendable effort! You should always be sure the PSU you purchase is compatible with the system you’re running. As of today I've been running my pre-modified GM620SC sample for aprox. 30-days without any problems whatsoever. While this is not evidence it's ok to go out purchase the pre-modified version and expect the same results, it has not caused any damage to my system. Skyhawk's Power One GM620SC can be found at Newegg for 89.00 USD.

While I can't think of many 620W PSUs constructed as well, as silent, or with as much potential for under $90, perhaps waiting for the revision may be best. If you have an older system Socket A, 754, 478 etc, this may be a steal, but check with the company first describing your system. As soon as the revised units become available you can be sure we'll have a review for you. I would like to thank Beverly and Sharon at SkyHawk for providing the unit for review.

This article has been updated with more information please read the following page by clicking on the "next" button at the bottom

Questions/Comments: forum thread
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