Specs and initial thoughts
The five PSUs being looked at consist of a pair from Enermax, another duo from SilverStone and a lone unit from Tagan.
These products aren't cheap. They range from £115 up to an eye-watering £224.
However, what the designers had in mind from the drawing-board stage were systems kitted out with next-generation graphics cards and processors and huge disk-arrays.
Let's see how the power supplies line up.
Enermax Galaxy 850W |
Enermax Galaxy 1000W |
SilverStone Zeus 750W |
SilverStone Zeus 850W |
Tagan Dual Engine 800W |
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Rated output power |
850W |
1000W |
750W |
850W |
800W |
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Power specification |
ATX 2.2 / EPS 12V 2.91 + Future 2007 EPS12V |
ATX 2.2 / EPS 12V 2.91 + Future 2007 EPS12B |
ATX 2.2 / EPS 12V |
ATX 2.2 / EPS 12V |
ATX 2.2 / EPS12V 2.9 |
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Power switch? |
Yes |
Yes |
Yes |
Yes |
Yes |
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Input voltage (AC) |
100-240V, 50-60Hz |
100-240V, 50-60Hz |
Autoranging 90-264V, 47-63Hz |
Autoranging 90-264V, 47-63Hz |
Autoranging 100-240V, 50/60Hz |
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Fan(s) |
135mm intake + 80mm exhaust |
135mm intake + 80mm exhaust |
80mm |
80mm |
2 x 80mm |
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Cable runs |
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Max combined 3.3V & 5V output |
200W |
200W |
180W |
180W |
180W |
All of the power supplies we're looking at can run on 240V or 110V and will automatically detect the input voltage and set themselves accordingly. That way of doing things avoids unhappy accidents.
Of the five PSUs, only the two Enermax models use modular cabling - an arrangement that has upsides and downsides. Modular cabling allows you to attach to the PSU only the wires you need and that makes it easy to route cables and create a tidy layout.
[advert]You also have a much wider range of cables to choose from. Although you can only plug in a certain number at any one time, you have some choice over which +12V rail you're going to plug each cable run into.
However, modularity adds an extra electrical connection and that can be generate noise or, sometimes, an unstable current after you've connected and disconnected the wires many times.
Since the Tagan and SilverStone PSUs have fixed cabling, there's no risk they'll suffer these problems. However, you will find it harder to do a tidy build with all those unused cables needing to be tied back and squirreled away.
The Enermax PSUs come with four PEG connectors, two of them modular. You'll need these if you're intending to build an 8800 GTX SLI system, as each card takes a pair of PEG connectors.
We found both the Enermax supplies to hold very stable voltages on the rails while under load. This bodes well for anyone looking for a supply that can run multiple high-end graphics cards.
Our SilverStone Zeus 750W sample only had a pair of PEG connectors but converters were supplied to bring the number of PEGs up to four. However, the latest retail versions that are shipping, such as the Zeus 850W, have four PEG connectors hard-wired.
The Tagan 800W is the odd one in the bunch, having only two hard-wired PEG connectors. So, for an 8800 GTX or 8800 Ultra SLI setup, you'll need to use converters supplied with the graphics cards to power the second card.
As you can see from the chart, Enermax cites some impressive figures for its Galaxy 1000.
There's a hefty 6A on the 5VSB, compared to 3A on the other supplies; and 30A on the 3.3V, compared to 24A on the SilverStone and 28A on the Tagan.
More impressive, though, are the Enermax's five 12V rails, each carrying 17A. The other PSUs only run four 12V rails. Each of these is of slightly higher ampage than the Enermax's but the Enermax 1000W should give you more power to play with overall. If, that is, it performs to the stated specs.