GM470PC | GM/570PC

Introduction

SkyHawk designs and builds numerous PC products including several Patented accouterments. Their Mini-PC IMC 6389 for Socket-775 incorporates a pre-OS active TFT screen mounted on an electronically operated (lifting) door. SkyHawk also market's several lines of PSU's today were testing two models from the GM-PC Series...



Our last SkyHawk PSU review featured the GM670SC the unit had the look and feel of raw power but fell slightly short on the 12V rail. In all fairness there were a plethora of components drawing current off the line including an H20 system utilizing the Alphacool AP1510 which uses a 12V ~ 24V which was set to 18V.

Several months prior to the GM670 review we also reviewed the Power One GM620 which was the object of some scrutiny by another site. I criticized that site's review then retracted in the name of harmony, I've regretted that decision which is found in the GM620 Update.

The GM620 wasn't in compliance based on the 240VA safety guideline which then requires split plane PSU’s with multiple 12V-Rails to use independent solder points from the PSU circuit board. Only in this manner can each leg be separate and therefore limited to 240VA and 18A, as is outlined in some of my comments in the article that stirred some controversy covered in the EPS 12V Power Supply Design Guideline (Sec 6.1.1 Split Plane .pdf). Sky Hawk’s failure to meet the guideline was prima facie how and why that article came to be is another story, suffice to say I was a PT writer there and terminated my position shortly thereafter. What was lost in the process of self-promotion at the expense of SkyHawk was an opportunity to critique a questionable Guideline. Sky Hawk's failure to meet that guideline pales in comparison to the damage done to both consumers and the industry by virtue of the Guideline itself. In a multi-rail design regardless of the number of 12V solder points there is till just a single transformer or singular source of 12V current. Multiple solder points from the PSU circuit board do little beyond meeting an impracticable wiring standard for an inefficacious engineering guideline since there's just one transformer and an electronic gate dividing (or switching) current to these 12V rails.

To gain some more insight on the matter, read ”SPCR's Confused about Dual 12V Lines?” this is a clear and well written piece. The photos below were taken of the GM470C reviewed here today; it’s clear SkyHawk has eschewed the 240VA standard using a single solder point.



Since the advent of the EPS12V PSU guideline PSU design has been hamstring, motherboard makers have been forced to use multi-VRM conversion to alleviate the ripple off the 12V line. These circuits herein lay the quandary, as I've been stating recently the issue has come to a head. With Intel's introduction of the world's first .65-micron process CPU ala Presler, motherboards have been dropping like flies in the stability department and in many cases without any overclocking or over-volting involved. Today’s units at 570 and 470 Watts wouldn't be recommended for a Dual Core processor such as the Intel Pentium-D. Today we'll be testing the GM470 and GM570 on the Asus P5ND2-SLi Deluxe running SLI with two Asus 6600GTs which draw their total current from the PCIe slots.

Packaging

The Power One power supplies arrived in perfect condition.



As usual Sky hawk does a fine job packaging their units, with bubble wrap, modular cables, mounting screws and an 18-guage power cable.




A word about power cables

The issue of power cables wasn't something I'd really considered until PSU's reached the 850W level. While that's not relevant here, for future reference at 850W or above when the PSU is drawing peak current a 12-guage power connector would be ideal, 16-gauge is what PCPower&Cooling provided with their TurboCool 850 SSI and I've not had any "noticeable" problems. 18-gauge is about the smallest for any PSU.

Both Skyhawk units are modular, and while there will be power loss on most modular "plugs" the net effect is worth it for the ergonomic benefits. While the PSU doesn't meet all "split plane" requirements it does offer an 8-pin and 4-pinout CPU cables as indicated below.



I always prefer a power switch on the PSU itself. So long as the switch is executed properly there's no need to unplug the PSU to clear your CMS or change out graphics cards. Be sure to turn off the switch then depress the main power switch on your PC-case to discharge any residual current from the capacitors. I've seen some PSU's have enough left to spin and illuminate an LED case fan for a few seconds.



The blue LED does give the unit a pleasant appearance in conjunction with its brushed steel exterior.



The cabling provided with both units is identical: 2x S-ATA ( 2x S-ATA connectors per cable), 2x Molex (2x molex connectors per cable) and finally one PCIe cable, with a single 6-pin connector. Obviously Sky Hawk didn't intend the GM470PC or GM570PC to power an SLI system. Of course that's exactly what I did in the spirit of stress-testing. I use a pair of Asus N6600GT Extremes which do not require a 6-pin external power source. No doubt the additional 75W PCIe slot will tax each PSU when used.



Specifications

Since both units are new Sky Hawk has not listed any specs on their site just yet although the stickers found on the PSU's have most pertinent info. Clicking on the thumbnails below will provide a close-up of each PSU specifications.

GM470PC | GM570PC


For more info Sky Hawk has supplied GM470PC/GM570PC Datasheets (.pdf).

Sky Hawk's thinking "inside the box..." ->