Tom's Hardware Guide published a review on Experiment: Build a (Profitable) Ethereum Mining Rig From Spare Parts A quote from the article:

Ethereum's mining difficulty is on the rise, & the crypto-currency's value is on the decline. Is it too late to get into crypto mining just to make a few bucks?

 Experiment: Build a (Profitable) Ethereum Mining Rig From Spare Parts @ Toms Hardware