X-bit labs

ATX Power Supply Units Roundup. Part VII (page 10)

Category: Other

by Oleg Artamonov

[ 09/04/2007 | 10:40 AM ]

In an earlier review I mentioned a small card in Epsilon PSUs that created a load on the PSU when it was started up. Otherwise, some mainboards could not start up because they did not provide the load necessary for the PSU to function normally at first. This load used to be provided by ordinary resistors that were turned on all the time, but this affected the efficiency at small loads. Moreover, the resistors get hot at work.

The Epsilon 700 has this card (it is covered with heat-shrinkable film and looks like a black square in the photographs) but the Epsilon 800 and 900 have not. They only have an empty slot the card used to be plugged into. We can’t check the PSUs out with many mainboards to see if the compatibility problem has vanished, but I suppose components that may need as much as 800W of power do consume a high enough current from the PSU at the start anyway.

Each of the three PSU models has four output +12V lines, but there is only one +12V power rail inside the PSU. The purpose of each line is marked on the label and the cables of the lines are color-coded (yellow, yellow-green, yellow-blue, yellow-black).

The more powerful units have a proportionally higher load capacity of the +5V and +3.3V rails as well as of the +12V rail.

Although the label seems to suggest that the max combined output power of all the +12V lines equals the PSU’s total output power, it is not exactly so. There is a limitation written in small print below: the load on the +12V must not exceed 70A for the 900W model. This means 840W rather than 875W as you might have thought.

The FSP Epsilon 700 offers the following cables and connectors:

• Mainboard cable with a 20+4-pin connector (54cm)
• CPU cable with a 4+4-pin connector (55cm)
• Two graphics card cables with 6-pin connectors (55cm)
• Two cables with three Molex connectors and one FDD mini-plug on each (50+20+20+20cm)
• Two cables with three SATA power connectors on each (54+21+21cm)

All the cables are sleeved.

The senior models, Epsilon 800 and Epsilon 900, have more connectors:

• Mainboard cable with a 20+4-pin connector (55cm)
• CPU cable with a 4-pin connector (55cm)
• CPU cable with a 4+4-pin connector (55cm)
• Four graphics card cables with 6-pin connectors (55cm)
• One cable with three Molex connectors and one FDD mini-plug (52+15+15+15cm)
• One cable with three Molex connectors (51+15+15cm)
• Two cables with four SATA power connectors (56+15+15+15cm)
• Two adapters to 8-pin graphics card connectors

So, there’s everything necessary here and the cables are long enough for any system case.