The front of the
unit during the first few minutes of test one. The room was 25 °C, but
that quickly changed.
not very often I get to review a truly "novel" power supply
unit. But this weekend I'm taking a look at an external power
supply unit from
the folks over at SevenTeam Electronics.
way this unit works, there's a metal plate with cables for PC
peripherals that bolts in place of a typical power supply. This
unit then sits outside of the PC and connects
to the back of that plate
of three modular cables.
This is the back of the ST-500EAZ.
concept behind this is to move the heat generating power supply
to the outside of your heat generating PC. By self-containing
the power supply, the only heat the unit is subject to is it's own.
The bottom of the unit features gold trim rubber feet reminiscent
of better audio equipment.
sure a lot of you are aware that I have a bit of an affinity
with SevenTeam. In my experience, SevenTeam makes very solid,
highly efficient units. Unfortunately,
their representation in the United States gives Seventeam a bit
of a bad rap. It seems that almost all of their products are "over-rated." The
Cooler Master eXtreme Power 600W is actually only a SevenTeam
ST-500BKV, the XG Duro 900W is actually only a SevenTeam ST-750EAJ.
Where long hold up, continuous rated power is what's typically
put on the label by SevenTeam, it seems that a 500ms peak power
is what's put on the label by the importers.
the only "honestly" rated SevenTeam re-label I've seen has
been the Sytrin Nextherm 460W, but because of it's "honest labeling" sales
may be suffering. In fact, I have a friend at a reseller that
told me that he had to drop the unit from his power supply line
up, because it was considered over-priced for a 460W unit.
It's ironic that if Sytrin just slapped a 550W sticker on the
side that they
would be doing nothing different than what the folks at Cooler
Master and MGE/XG are doing and the product would likely sell
like hot cakes.
way this external unit is marketed in the U.S. doesn't seem
to be any different than the other SevenTeam built products
I mentioned. This unit is sold by the XG division of MGE as an
600W unit. If we have a look at the
label on the unit Gabriel
Torres' previewed at Hardware
Secrets, we can see the same
"ZJB500EAZ" serial number prefix underneath the rail table
that we seen on the SevenTeam label
Specifications as per the PSU label:
Max Combined Watts
* Shortly after
I received my sample, the specs on the SevenTeam
this unit with 22A on he +12V2.
calls this PSU "semi-fanless." There's a big honkin'
80MM fan inside the housing. The fan doesn't spin often. In
fact, in normal PC use
the fan only spins during heavy battle. Web surfing, word processing
and the like should not provoke the fan to turn on. Furthermore,
when the fan is spinning, one can barely hear it, probably
is not mounted to an outside panel of the unit. It's stashed
just behind the front LCD panel, directly in front of the heat
Yes Virginia. There IS a fan inside. We'll look at more inside
of LCD; just in case the fact that there's a big aluminum box
sitting on top of your case wasn't cool enough, the LCD on
of this unit tells the user the ambient temperature of the
the estimated power output of the unit and at what voltage
one of the 12V rails may be at. We'll discuss the LCD a little
now, let's have a look at those cables... starting with the
three thick external cables...
The wire colors tell us that this isn't your typical pinout.
external cables use standard connectors, but they are quite
on the back of this unit is unlike any standard in the industry.
Why are there three external cables? I'm not sure why they
just do two (like two 24-pin cables) or even one big one
(like put two 24-pin cables in one casing) but there are three
cables with nearly unfinished ends (they could've done better
than heat-shrink, in my opinion.)
thing to note is that these cables are only a little over a
foot long, so the
unit isn't going to go far from the rest of your PC. It's
likely to just sit on the top of the case. I don't believe
to be able to put this box on the floor next to your PC unless
you have an upside-down case and it's not going to make it
top of your desk if you keep the rest of your computer down
on the floor.
The cables aren't very long and therefore do not allow for very
remote location of the power supply.
cables on the inside of the PC are a whole other story... one
with a very similar plot....
cables that enter the inside of the case are simple sleeved
units. Again, with ends that are hardly beauty
pageant material. Like the external cables, the ends are heat-shrink
wrapped with a considerable amount of wire exposed. Regardless
are decorated, I had to think about why they wouldn't
with a modular
with a modular interface on both the back of the power supply
and the back of the case, there would be considerable
resistance created by adding yet another modular interface.
But with fixed cables inside and no power supply in place to
cables up on top of, the user is left with a real mess
inside their case. What they should have done is made at least
one end of the OUTSIDE CABLES fixed. You need all three.
You're not going to "use
only the cables you need" on the outside, and if the cables
on the outside were fixed, they'd look better too! This is
a major fubar on SevenTeam's part and it's going to make judging
aesthetics difficult. Certainly, the cool factor of having
a power supply on top of your case with a glowing blue LCD
is high on the bling-o-meter, but all of this cable mess makes
me want to vomit.
The above metal plate bolts in place of where a power supply
would normally go.
included with power supply:
Type of connector:
2 x 2
2 x 3
Drive power connectors
connectors (thermostatically controlled 12V only)
The +12V 4-pin and EPS 8-pin are paired up on the same cable.
The two PCI-e's are also on the same cable. I'm not sure I like
We're almost to
the load tester portion of the review.....
I decided it
might be neat to graph the actual wattage vs. the wattage
displayed on the LCD. So on the next page you'll see that there's
two columns. One labeled "actual wattage" and another
Have any of
you guys ever installed an ammeter
in a car? Remember
how the ammeter hooked up between the battery's positive terminal
and everything else in the car (typically an older car or your
weekend race car w/ minimal electronics)? That's how it measured
amperage. Because all of the amperage of the
it can tell you how much juice your car is pulling from the battery.
But if you hook something up that by-passes the ammeter, you can't
gage it's usage.
For a power
supply to accurately tell you how much wattage it's using,
it would have to measure all of the DC amperage being pulled
from each peripheral connector. And because a power supply supplies
multiple DC voltages, you'll essentially need an ammeter for
each rail. Multiply the Amps you've measured by the voltage
of each rail, add them
your total wattage. Guess what? It's quite possible, and there
are devices that will do this, but it doesn't fit in a standard
ATX power supply housing... or a Seventeam external power supply
housing for that matter.
typically done when a power supply has a wattage display is the
AC input wattage is measured with a built in ammeter. A calculation
into account. It is the sum of
this equation that is displayed. So not only is the number going
to be off because efficiency can vary based on temperature, but
because efficiency is not a linear number. It is actually
on more of a
as load varies (typically low efficiency on low and high loads
with the better efficiency in the upper 70% of the power supply's
capability,) the number on the display can be quite off.
The power supply, simply plugged in, shows a 22W load from the
now for the load tester portion of the review....
you're not familiar with the way I load test power supplies,
supply load tester. It's the kind of equipment power supply
manufacturers use to quality assure units. My tester allows
me to pre-program
five different loads on six different rails at a time. The
load tester can then report the voltage of each rail it's
typically keep -12V with a .5A load and +5VSB at 2.5A. The other
four rails are the ones I fluctuate for testing purposes. Those
rails are +3.3V, +5V and the two +12V rails. Each test is run
for an hour before readings are logged.
run the power supplies on a bench in a 25°C
room. Normally, that's a flaw in my testing methodology because
the power supply I'm testing isn't sucking up the heat coming
off of whatever I'm powering (I really should make a duct
going from the load tester's exhaust fan to the intake fan
of the power supply.) But since I'm looking at an external
power supply and the hottest thing in the room IS the power
supply, the fact that the power supply sits on a bench doesn't
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