My last post on the ROI for mining Litecoin with the new R9 290/290X GPUs is still more or less on target -- difficulty is stabilizing for now, with an expected return of around 2 LTC per week per R9 GPU. That works out to around $45 per week, or $180 per month, so you'll have paid for your R9 290/290X in three months, give or take. But what about switching to some alternative cryptocurrency?
In roughly one week of mining, I mined about 1 BTC with 7000 KHash of GPUs. That works out to over $700 per week for hardware that you could match with seven or eight R9 290X GPUs, eight or nine R9 290 GPUs, or ten R9 280X GPUs. Now if you do the math, at present that means best case you would need $4600 worth of R9 290X cards, $4000 or R9 290 cards, or just $3500 worth of R9 280X (HD 7970) cards. Until prices are closer to MSRP, it looks like the 280X is the one to get.
Now, if current alternative cryptocurrency mining remains even close to where it's been, we're looking at roughly $2800 per month, so you'd pay off the GPUs in less than two months, and realistically all of the hardware could be paid for within two months. That's pretty darn appealing if you ask me! And you don't have to go out and buy dozens of cards in one fell swoop either -- just start with a single rig and if you go with 3-way R9 280X you could have the whole system for around $1500, and it would be paid for in about six weeks.
The problem is Hashco.ws is still in a state of disarray following the hack, so I've moved to Middlecoin for now. I switched about 5000 KHash of PCs to Middlecoin six hours ago, and at present it looks like my BTC balance is 0.0135 BTC. For a full day of mining that works out to 0.054 BTC, which would yield roughly $40 per day, $1200 per month -- not quite so rosy. I'll update tomorrow when I've seen just how many BTC I get through Middlecoin after a full day of mining, as it could still be ramping up my payouts; I'm hoping to get about twice that (0.1 BTC per day), which is closer to my previous rate with Hashco.ws.
Update: I've switched most of my systems back to Hashco.ws as the primary pool, with Middlecoin as the secondary pool. Hashco.ws is still a bit of a pain, as you can't log in to create new workers, and if you don't have an account already you're out of luck until they get the front end to their site working again. However, I'm getting payouts of around 0.075 BTC per day from Hashco.ws, and Middlecoin is typically providing another 0.015 BTC per day. So around 7000KHash/sec is generating 0.09 BTC daily, or close to $70 per day in income. Power costs are around $400 per month for my systems, but modern R9 builds should be more like $200-$250. Net income per month thus works out to $1500-$2250.