I have an HP g3 mini and a Dell Optiplex flying around, both similarly specced. The HP has an i5 6500t and 16gb DDR4 RAM, the Dell has 8gb DDR3l, so nothing too different.
However, the Dell draws around 15W while idle, the HP one 5W.
The only difference I could think of (and that is in my power to change) is the PSU. The Dell has one of those SFF PSU for up to 180W while the HP has an external 65W power brick with a barrel jack.
So my question is: Does anyone have experience with one of those Pico PSUs? I guess they should be more efficient? I’m not planning to put anything power hungry into the optiplex.
At current power costs in Germany (~0.3€/kWh) that 10W becomes 26€ per year. If you are still on a contract from a few months ago (~0.4€/kWh), you’ll be paying ~35€ per year. Over a span of around 3 to 5 years of continued use, the cheap Aliexpress knockoffs definitely become reasonable at that price point. You’d still need a proper 230V to 12V PSU though, which costs <20€. I first tried one of the industrial ones with metal cage, but they have horrible efficiency especially at low loads. I would always suggest getting a consumer PSU with ErP rating and other certifications. Adding all the cost up, a good regular ATX PSU with 80PLUS certification might be competitive to such a combo too.
I am not too sure this problem is entirely about the PSU though. Maybe the mainboard is simply designed very cheaply and inefficiently. There’s no way of testing a new PSU combo without trying it though.