X-bit labs

1000W Power Supply Unit Roundup (page 13)

Category: Other

by Oleg Artamonov

[ 05/02/2007 | 08:46 PM ]

Topower PowerTrain TOP-1000P9 U14 (1000W)

The PowerTrain TOP-1000P9 U14 is a second unit out of the six included into this review that is equipped with a 135mm fan (the Cooler Master Real Power Pro was the first one). Hopefully, it will be noiseless – we’ve already found out that the PSUs with 80mm fans can’t be quiet…

This PSU uses a design with two transformers working in sync, too. It is equipped with active PFC and features independent voltage regulation. These two features are in fact standard for PSUs of this class.

The heatsinks of this PSU aren’t as fanciful as in the Tagan, yet they are remarkable, too, consisting of a large number of small vertical corrugated ribs.

Having a total wattage of 1000 Watts, this PSU can deliver up to 900 Watts (75A) along its 12V power rail, which is divided into six output lines. And like with other new PSUs from Topower, this division is very tenuous.

There are current-measuring shunts next to the output cables on the PCB (the thick U-shaped strap in the photograph above). The signal from the straps should go to the current limitation circuit so that if there is a current of over 18A on one strap, the protection shuts the PSU down. I call this implementation “virtual splitting”: there is one +12V power rail, but the load current is deliberately limited on the output connectors.

So, the TOP-1000P9 has those shunts but has no protection. If the current in one shunt is higher than 18A, the “Combined” indicator on the front panel of the PSU will light up. That’s all – nothing else is going to happen. Of course, there is no “automatic combining of the lines” here as you can read in the advertising materials. You can just regard the PSU as having had no separate lines beforehand. This is not a technical drawback. It is rather interesting from the marketing point of view: the manufacturer wants to make its product appealing as having the advantages of models with multiple +12V lines (which are actually imaginary advantages because the division into multiple lines has no effect on stability or cross-load characteristics) as well as those of models with one +12V power rail.