As it turns out, virtually all electric heating is equally efficient (in terms of electricity used per unit of heat outputted). The only difference is that with electric heating, the desired output is the heat itself. While as with computers, the desired output is some kind of audio/visual signal with heat being a generally undesired byproduct.
So during college, I repurposed my desktop PC to mine crypto instead of turning on the (electric) heat in the apartment. I ended up making ~$60 worth of crypto in about 1-2 months before I stopped mining crypto because the fan noise was unbearable.
