I just replaced a 465w PSU with a 520w PSU.
Why did you replace it? Being as specific as possible might
help. If you feel your system "needed" more power, it might
help to describe all major power consumers in the system,
for example CPUs, drives, video cards, and if anything
unusual or exotic like peltier coolers, even more
device-specific information about those like current per
voltage specs, control methods, etc.
However, the grid on the side
of the PSU would lead me to believe that I just "downgraded" the PSU.
To be concise, there is little point reading the label on a
PSU unless you already have reason to specifically, trust
the label. In other words, randomly grab a PSU and odds are
quite high the label is not accurate. In short there needs
be a standardized method and legal repercussions for PSU
rating- it is LONG overdue to prevent the potential fraud
occuring persistently in the industry from even most
respected parts distributers.
The original, a 465W Enermax, shows the following:
First, Enermax rates at 25C ambient temp, and it's quite
unlikely the ambient intake temp is that inside your system.
One must derate for it to lower wattage but further, one
must also know the ambient temp rating of the OTHER PSU
being compared. In theory, if one built two identical PSU,
one could carry a label claiming "350W" but it's spec'd to
do so at 35C, while another claimed "420W" but is spec'd for
it at 25C. The matter is far more difficult when the PSUs
aren't identical.
Further, Enermax does not rate for sustained output. They
rate for 70% output to achieve the MTBF rating at 25C.
Doing a crude calculation only as an example, that's .7 *
465 = 326W. Sad but true, but it gets worse below...
+3.3V 36A
+5V 44A
+12V 20A
-5V 2A
-12V 1A
+5VSb 2.2A
This PSU is somewhat of a compromise, it's meant to support
a fair (but not really high) output on both 5V+3V and 12V
rails. It would be suited for most mid-range systems made
in the past several years, but not overclocking or more
high--end parts, nor a generally well-endowed system with
lots of cards and drives unless the parts combination just
happened to fairly evenly load both the major power rails
instead of disproportionate draw from one far more than the
other. In a modern system, that is often the case
especially with multiple drives and a gaming video card,
that the 12V rail is under more load and above PSU may start
showing signs of weakness.
The replacement, a 520W Aspire, shows:
Aspire is a generic relabel, often with extra eye-candy
added to make it more marketable and present an impression
that it's more similar to other higher-end PSU. Pity they
didn't spend the construction budget on the internal power
supply related functions before spending on the marketable
eye-candy. There are also more pedestrian looking Aspire
that omit the eye-candy and are a more reasonable value but
they are also rated unrealistically, perhaps even moreso
than the Enermax. So all things being equal, the Enermax is
a little better quality but has a bit different amperage
distribution so direct comparison for a specific system
isn't necessarily possible, at least unless one knows the
actual draw of the system.
+3.3V 28A
+5V 30A
+12V 34A
-5V 0.3A
-12V 0.8A
+5VSb 2.0A
I thought my original PSU was starting to die,
Based on what evidence?
Generally a multimeter reading(s) of voltage levels at the
load are a good first step towards determining adequacy as
being compared here, not only total output but also amperage
capacity as a % of total as briefly mentioned above
regarding 12V current.
The Aspire is not a good upgrade, but without knowing the
parts being powered, it's not certain you actually needed an
upgrade, rather we don't know the target, and the PSUs'
misleading specs compound the problem of finding suitable
supply for that target.
so I bought a replacement.
Did I just go backwards?
Depends on how you look at it. Suppose you buy a candle and
find you need more light, so both ends are lit. Candle
burns out twice as fast, maybe far faster since it's turned
sideways but we'll ignore that detail.
Once candle is gone, you look at a replacement... could buy
another candle that has to burn at both ends, and it would
be a better choice merely because it's fresh/new, not burnt
down (worn out), like the Enermax might be at this point.
So from that perspective your new PSU is an upgrade in
functionality over the present state of the old PSU.
That doesn't necessarily mean it was a good choice though,
compared to a candle of suitably larger size that need not
be burnt at both ends. A PSU suitably sized for a system
should be expected to run for about 10 years, though less if
the system has poor cooling design such that PSU runs
hotter. Recall above the derating for higher temp, it is a
very real and clear relationship comparing two identical
PSU, but the different PSU introduce further variables.
Speaking of variables, there are too many to provide a clear
answer to your situation. The Aspire is not regarded as a
decent 520W PSU, ironicallly enough it's closer to same as
other psu rated at lower wattage but costing same. If
anything, the major PSU manufacturers are the ones who
secure volume contracts on good quality parts at low prices,
it is often a false economy to buy a generic. Some brands
do have a slight additional overhead coming from 3rd party
marketing and profit margins (for example Antec, does not
make their PSUs) but it is also a certain assurance of a
quality level... at least one hopes so.
If you really need(ed) a PSU capable of 34A on 12V rail,
expect to pay over $100 for it. I doubt you need that much
though, but the beginning is to determine what you do
actually need, then choose a supply that has a rating system
one can rely on, or that one knows a derating-table for so
they can factor for it. Even so, many generics have other
problem areas like higher-ESR capacitors that are more prone
to failure (shorter life) and fan seizure.
If you keep the Aspire, I would at least replace the rear
exhaust fan with a quality name-brand (fan manufacturer
brand, not PC-parts brand) dual ball-bearing fan of similar
RPM & amperage rating.
