Here’s an idea of what the picoPSU-80 setup draws from the wall when connected to a Pentium III 800 MHz machine with 512 MB RAM, a hard drive and a floppy drive.

It performs surprisingly well.

I should really repeat this test with the machine under a meaningful CPU and disk load to see how high the power consumption actually gets.

The picoPSU was first tested on the Amstrad Mega PC a few months ago with an adapter to suit AT-style power supplies. It worked well then, but I did not have access to a power usage meter.

Now I can check the juice that is being eaten by whatever device is attached.

Load monitoring is quite important. The picoPSU-80 has an 80 W overall rating, but individual rail limits and the capacity of the external 12 V supply also matter. An overloaded setup may become unstable, shut down, overheat or potentially damage components depending on which limit is being exceeded.

The wall-power meter also includes losses in the external AC-to-12 V power brick, so its reading is not the same as the DC output load on the picoPSU itself.

Sources

  • Mini-Box picoPSU-80 - manufacturer specifications for the 80 W DC-DC ATX supply, 12 V input and individual output limits.