So I started mining in June when the hype was big; I managed to get together a crew of six high-end AMD GPUs and was really hoping prices would stay high. I did manage to cash out and pay for all the hardware, but then the price died on me. So sad. Now I'm just hanging around looking at BTC from afar and wondering if there's a reasonable chance of making money. I've got about 40 BTC left that I'm thinking to play with as speculation, but all of the miners are shut down. (Hint: drawing 2000W of power at $0.08 per kWh for 1.2BTC per day means that I'd have to see BTC prices of at least $3.2 just to break even; realistically I'd want it at $6 or more given the volatility.)
Wait 2000W for ~1.5GH? Are those graphics cards or lead smelters?
3x5970 are <1000W and push 2300MH/s+.
Well, the power is an estimate. I've got three systems with two x16 slots, so the net result is 1 x 6950, 2 x 5870, 2 x 5850, and 1 x 5670 (not so high on the last one, but the slot will only fit a single wide card). All are slightly overclocked, but to varying amounts. Actual power draw is probably closer to 1200-1500W, but the three systems have a 550W, 700W, and 750W PSU. Either way, even if it's only 1200W total (which is probably a bit low), the result is that I can hash around 2000Ghash/s. When I quit mining, difficulty was a bit higher so that worked out to around 1.2BTC/day. Looks like with the drop in mining power I'd now get 1.5BTC per day. So, let's see, best case I can mine maybe 1.5BTC per day for an electrical cost of $2.3; if my estimates are a bit too low on power (so closer to 1500W than 1200W), we'd be at $2.88 per day. Given the volatility of BTC right now, I can't sink a bunch of extra money into mining in the hopes of recouping my costs.
What I do know is my power bills were up about $125 per month, which works out to closer to 2200W of power draw. Rather than put the extra money into mining, I'm seeing if I can speculate and increase my BTC holdings that way. So far, not so good, but I've decided to be a bit more cautious after some stupid decisions early on and I managed a 2% increase in BTC today. That works out to around 1BTC for zero cost in electricity, which is better than 1.5BTC for $2.30 in power bills.