Reviews - The Bargain Basement Power Supply Roundup
(By Oklahoma Wolf on Fri, Sep-14-2007)
Page 1 -
For years, the DIY'er has sought to build his PC using the best parts around that will fit into a certain budget. Many times, the power supply is considered an afterthought, due to the willingness of case manufacturers to throw one in for free or sell one on the side for dirt cheap. After all, power is power right? Who needs to shell out vast amounts of currency when surely that cheapie Happy Diamond Moon Gigglepower 650W can do the job too?
Granted, most of the people reading this article are aware of the multiple reasons why one should not look a gift horse... er, PSU in the mouth; but we here at jonnyGURU.com thought it would be fun to run seven of these "almost free" wonders through the wringer and see what happened. We'll throw each one onto the SunMoon SM-8800 ATE, apply the same battery of eight tests to them, run them through the incubator hot box (if they make it that far), and see if we can pick something halfway decent by the time the article is over. Most of these units were obtained through a contest we ran in the forums for a while, known as the "Pimp My Power Supply" contest. A person would nominate his power supply for consideration, a vote would be taken, and the winner would get his power supply swapped for whatever high end unit was up for grabs that month.
Note that while we did do ripple testing on these units, only the more spectacular scope shots will be used to conserve space. After all testing is complete, we'll pull the dead units apart and try to find out what failed.
A quick word about the loading of these units: we're going to go by the ATX spec sheet in determining our load levels. We're doing this because a lot of these units will be out there powering newer 12V based rigs, despite most of these being much older units centered around the 5V and 3.3V rails. Many of these won't like such treatment one bit, and often we'll be seeing loads on some rails that exceed what's printed on the label.
So, is everyone ready for the fun to begin? Excellent. Let's proceed alphabetically and start with the...
We're starting things off with a resounding thud today, aren't we? This lovely example of SMPS engineering can be found here and there for as low as $9.99. While common sense might dictate that there could be no way such a cheap unit could do 650 watts, price isn't always indicative of a hunk 'o junk as evidenced by the prevalence of free or close to it after rebate supplies out there, like those offered by Ultra. Would the Chiefmax turn out to be a wolf in sheep's clothing or the other way around? In a minute, we'll see for sure. But first, looking at the above picture, we can spot several clues that can already give us a pretty good idea.
The first thing up there that stands out for me is the little bulge in the cover near where the wires exit the unit. This told me the metal used in construction was quite flimsy, and indeed after I got the cover off it I found that I could bend it with my thumb between two fingers on one hand. Second, it's light. Really, really light. I've known heavier paperweights. Third, take a look at the wiring - that's twenty guage wiring there, folks. Even to the 20+4 pin ATX connector. Another bad sign... it takes something thicker than this to haul around the currents being promised by this thing. Speaking of currents, here's a chart:
Max Combined Watts
Yes indeed, the specs on the label promise us the moon. 408 watts on the 12V alone. The label lists no combined ratings at all, just the promise of 650W output capacity. Already, I'm having trouble believing the hype. The lack of any sort of agency approvals on the label whatsoever doesn't ease my mind one bit. Let's get the cover off and see what it looks like inside.
If ever there was a sight that said "I can do 650 watts," it isn't this one. Tiny heatsinks. Low value input caps of unknown origin. Very few parts bolted to the heatsinks. Group regulation. OVP present but no OCP. Two 80mm fans of questionable air handling capacity. Tiny TEC brand caps on the secondary. Those of you with experience in these matters will recognize the unit as being a not so fine example of Leadman Power engineering, most often found under the name Powmax. Folks, the load testing phase is going to be fun.
Results from Chiefmax 650W COLD load tests
Simulated system load tests
Sure enough, after a few minutes of test one, we got an electrical zzzt sound and the unit was dead. At 184 watts, it died. Seems a long way from 650 watts, doesn't it? We didn't even get a chance at using the scope on this one, it went out that soon.
Let's go on to the next unit and see if we can get some better results. Or a better lightshow. Either way we'll be entertained, I'm sure.
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