Effective CPU mining of Bitcoin ended in 2010. Effective GPU mining ended last year. Now only highly-specialized ASIC hardware can mine Bitcoins effectively,

Effective CPU mining of Bitcoin ended in 2010. Effective GPU mining ended last year. Now only highly-specialized ASIC hardware can mine Bitcoins effectively, and even then profits are questionable at current hardware prices. Finally, the earliest farm mining of Bitcoins that I'm aware of started back in early 2011, and probably earlier (when did ArtForz start?).