OCZ PowerStream 520ADJ Power Supply
Date Posted:12/04/2005 12:43.55
In all three tests, the power supply did really well... load wise. The rails never fluctuated more than .5% and my load went from 298W to 488W. There were however some anomalies....
Discuss This Article
|OCZ PowerStream 520ADJ
||Test One (368.5W)
||Test Two (298W)
||Test Three (488W)
||Full Load (539W)
I ran into some serious problems and I didn't want to grade on a curve
or anything until I got some feedback from OCZ.
In all three tests, the power supply did really well... load wise. The
rails never fluctuated more than .5% and my load went from 298W to 488W. Power
factor was between .68 and .72 (not too bad) and efficiency hovered around
73 to 74%.
The problem reared it's ugly head during test two when the 5V load was
greater than the load on the 12V. At this moment, I noticed all of
the voltages bouncing back and forth by as much
as .2V or MORE! Although the voltages spent most (not
all) of their time at one number, this is something that would typically
tear up your computer hardware.
X-bit labes reflected the same results in their review too: http://www.xbitlabs.com/articles/other/display/powerful-psu_11.html To
quote Oleg: "when the load on the +5v rail became very high and on
the +12v rail very low, its regulator would lose stability, changing the
output voltages in a leap." That rules out that I got a bad
unit. Unless we BOTH got a bad unit.
I proceeded to test three. Everything worked great. Voltages
were stable for a good hour. I then cranked the 12V up to the maximum
specified amperage as per the label. This put the 12V at 33A while
the 5V was at 20A. No problems.
In an effort to perform my max load test, I then began cranking up the
5V and, just like clockwork, the rails started bouncing about so frantically,
there would be no way you could run a real PC off of the power supply. I
then proceeded to push the 5V up to 40A and the 12V dropped all of the
way down to 10.24V! I could stabilize the power supply by turning
the 12V up even higher, but temps were already at 47.3C which is hotter
than any other power supply I've tested so far! So THAT wasn't a
The only way I could do my full load test was to put the 12V to 33A, the
5V to 20A and the 3.3V to 8A. 539W is not at all a bad thing, but
it's not as much as I had expected.
If they said the 12V could do 33A, that's396W. That only leaves
124W for the rest of the rails before the power supply is at 520W. After
you take 28.4W away for .5A @ -12V, .5A @ -5V, 3A at 3.3V and 2A for the
5VSB, your left with only 19A on the 5V before you're at 520W. So
it's not as if we don't have a power supply that can do 520W. It's
just with a label telling me that the 5V could do 40A, but in reality only
being able to do half of that and only if the 12V rail is loaded heavier
at all times, I felt a bit let down.
I did get a response from someone at OCZ. The response (I'm sure
not an official respose either) was "because it is a true ATX12V2.0
power supply, it will exhibit this behaviour if the 5V is loaded more than
the 12V. If you anticipate 5V loads greater than the 12V load, we
suggest not using an ATX12V2.0 power supply."
Truth be told, it's not as if anyone would really load the 12V to 33A
and the 5V to 19A for ANY period of time, my concern was the voltage fluctuation
with a high 5V and where the heck the numbers on the label come from if
you can't even get the 5V up to 30A and stable when there's only a 10A
load on the 12V!
In a nutshell, all this would mean that the ModStream actually performed
BETTER than the PowerStream under the full load test, and would actually
be a better choice for someone with a 5V heavy system (like the one represented
in test two.) And given the 520ADJ is only really different from
the 420ADJ in that the 520ADJ gives you 10A more on the 5V rail... 10A
that you'd never be able to use, and only 2A more on the 12V rail; I think
it's safe to say that the 420ADJ is a much better value.
So thumbs up to OCZ on every power supply in their line up... except this
one. It's a good unit, sure. And it IS quiet (someone was bound
to ask.) But it's label is somewhat deceptive and compared to other
OCZ models, it's just not a good value. Put that in with the high
temperatures I was getting and we end up giving this mixed bag rating of 7.5.
Reviews, Articles, News, All Reviews...
Reviews, Articles, News...
A Guru's World, CPU/Memory Watch, SLDeals...
Forums, Register(Free), Todays Discussions...
Search, About Us, Advertise...