With the introduction of
SLI videocard gaming in early 2005, and the recent release of Intel and
AMD dual core processors, there has been a lot of focus on power supplies. A trick
that many generic power supply manufacturers use to boost up a PSUs overall wattage rating, is by
increasing the amount of power the 5V and 3.3V lines can provide while
skimping on the 12V rail. Unfortunately uneducated users are often easily fooled by 500W or 600W
numbers printed on the outside of the box, and fail to look more closely at
how the power is distributed across the individual rails. This has spawned a lot of users to complain of PSU
related problems in their local computer forums.
Here at PCStats we have long stressed that users look
beyond the *overall* wattage rating of a power supply and focus on its
individual 'power rail' amperage values. The number of rails will differ between models, but in all
current cases the most important one is the 12V rail. Both the processor and videocard (the
biggest energy hogs in a system) draw power from this rail.
A couple of years ago, a 500W power supply would be considered huge, these
days a 500W PSU with a strong 12V rail rating is required for high end systems, especially SLI-capable ones. It is amazing to see how high power requirements have
increased in the last little while.
When one thinks about enthusiast calibre power supplies,
quite a few brands pop into mind; PC Power & Cooling, Seasonic, Vantec and OCZ (both utilizing
Topower circuitry) are the first set I think of. AOpen is a brand that
enthusiasts should consider. The company is really more accurately described as a collection of companies, each
focusing on individual products, which has thus far translated well in terms of
The AOpen Prima Power AO700-12ALN is a rather plain looking power supply, but one which has
the ability to deliver a massive 700W of power
and four separate 12V rails! To sweeten things, the AO700-12ALN is also very quiet
thanks to the large 120mm fan generating 28.4 dBA at maximum RPM.
||AOpen Prima Power AO700-12ALN
The AOpen Prima Power AO700-12ALN is a standard
ATX sized PSU, and not noticeably heavier than an equivalent PSU in the 350W-500W range either. The AO700-12ALN adheres to
the ATX 2.0 standard which calls for a 24 pin main ATX
power connector as well as Serial ATA HDD power connectors and a six pin videocard power
connector. Those of you with older hardware are not out of luck, pins
21-24 can be detached from the main connector to fit older motherboards. We'll go into the
number of power connectors in a moment.
The most impressive feature of the AOpen Prima Power
AO700-12ALN are its quad +12V rails, all four of which have a maximum rating of
15 Amps. The +3.3V line can deliver 36 Amps and the +5V line 30 Amps, but
the maximum load of the +3.3V and +5V lines is 155W. The +3.3V, +5V and the four
+12V rails can output a maximum of 680W and the total peak output of the power
supply is 700W at an internal temperature of 35 degrees Celsius.
to AOpen as the temperature inside the PSU rises, the Prima Power AO700-12ALN's
maximum power output is lowered by 3W per degree Celsius and the PSU has a
maximum internal temperature of 50 degrees Celsius. This temperature value is
key to how some disreputable companies can get away with labeling junky units
with really high Wattage figures.... they do this by quoting an
unlikely low operating temperature for a specific Wattage.
Like many of the other power supplies that have passed through the PCStats
test labs, the AOpen Prima Power AO700-12ALN supports Active PFC (Power Factor
Correction). That means the AOpen PSU does not have the 115/230V switch on the
back and will work anywhere in the world right out of the box.