Quote from: dio on May 16, 2011, 10:54:44 AM

hi folks, i am still relatively new to bitcoin and trying to better figure it out. one of the things i don't understand yet is why the mining difficulty is raised so much that one seems to need super duper high end gears and GPUs to mine coins these days.

i understand that exact answers may not be possible, can can any of you give me an estimate of how much power is currently used to generate 1 BTC and how much it costs overall (including cost/depreciation of the rig)?

Currently you need ~160MHashes/s to generate 1 BTC on average per day. Power draw is somewhere between 1-1.5 W/MHash/s, so ~4-6 kW/day can be expected (a minig rig that small would have a bit more of overhead from other components, so I'll use the 6 kW/day further on)

Depending on your electricity costs you can roughly estimate a bitcoin currently costs between ~.50 USD and ~1 EUR in electricity to be minted. This is with GPUs though, that have a good Watts/MHash/s rate. With CPUs this would be a very different thing.

Also, as difficulty increases, you can use the increases easily in this calculation: Difficulty increases by 50% --> BTC minting costs 50% more.

Depreciation is hard to guess, as I'm not 100% sure how long a mining rig should depreciate (5 years? 2 years? 3 months?), and many people use their GPU for other things than mining too, so do your own maths.