Basically I got mostly a bunch of gear from the old Litecoin days. The good old and reliable 7950s, 7970s, 280x, etc.
Despite the DAG file slow downs, they hash close to 20MH/s (if you convert SIA back to your ETH) and use about 175Watts or so.
My 470s they hash close to 32MH/s (if you convert SIA back to your ETH) and use about 160Watts or so.
So as you can see they are about ~50% more efficient. From 9W/MHS to about 6W/MHS.
Yes I know you can get 4.5W/MHS with the 470s but they run almost 50% slower and ROI is a very important goal.
So the question is? To sell the 28nm gear and replace with 14nm gear?
The 28nm is all paid for many many times over. However the problem is that right now NOBODY is paying good money for used 7950,7970,280x because everybody is just buying brand new 470/480. The most I could get for my cards is around $80-100USD, at the moment.
So you can't sell 2 GPUs that hash total at 32MH/s and buy 1 GPU for the exact same price. You would have to take a loss and have a steeper ROI because you only would add a delta amount of hashpower to your farm since you are upgrading and not powering up completely new gear.
Now the upside is that the new gear uses almost the same amount of power but hashes 50% faster. So the 470 can make almost $1 more per day using the same electricity as the old gear. HOWEVER assuming the 470/480 2nd hand market is 50% off retail, you would have to mine with the 470 for at least 6 months before you actually start earning EXTRA profit compared to just sticking to your old gear.
Alot can happen in 6 months. Even if price accelerates you could of made that so with your old 28nm. So wondering what all the veterans are doing with their gear mostly. If the price crashes in the next month or so, you will be looking at a loss.
Even though the 28nm is more inefficient, by todays average power rates its still not much of a factor, since you make factors more then the electricity that's actually used.
So unless one has VERY expensive electricity rates I am talking about 0.20kwh/$ then it might be wise to just keep the old trusty 7950s mining away.
Despite the DAG file slow downs, they hash close to 20MH/s (if you convert SIA back to your ETH) and use about 175Watts or so.
My 470s they hash close to 32MH/s (if you convert SIA back to your ETH) and use about 160Watts or so.
So as you can see they are about ~50% more efficient. From 9W/MHS to about 6W/MHS.
Yes I know you can get 4.5W/MHS with the 470s but they run almost 50% slower and ROI is a very important goal.
So the question is? To sell the 28nm gear and replace with 14nm gear?
The 28nm is all paid for many many times over. However the problem is that right now NOBODY is paying good money for used 7950,7970,280x because everybody is just buying brand new 470/480. The most I could get for my cards is around $80-100USD, at the moment.
So you can't sell 2 GPUs that hash total at 32MH/s and buy 1 GPU for the exact same price. You would have to take a loss and have a steeper ROI because you only would add a delta amount of hashpower to your farm since you are upgrading and not powering up completely new gear.
Now the upside is that the new gear uses almost the same amount of power but hashes 50% faster. So the 470 can make almost $1 more per day using the same electricity as the old gear. HOWEVER assuming the 470/480 2nd hand market is 50% off retail, you would have to mine with the 470 for at least 6 months before you actually start earning EXTRA profit compared to just sticking to your old gear.
Alot can happen in 6 months. Even if price accelerates you could of made that so with your old 28nm. So wondering what all the veterans are doing with their gear mostly. If the price crashes in the next month or so, you will be looking at a loss.
Even though the 28nm is more inefficient, by todays average power rates its still not much of a factor, since you make factors more then the electricity that's actually used.
So unless one has VERY expensive electricity rates I am talking about 0.20kwh/$ then it might be wise to just keep the old trusty 7950s mining away.