So here is my 2cents on if this is worth it.
There was mention earlier of the prices for mining LTC with these USB sticks vs with GPUs. And noted that
after the power costs the average card would cost about 100 bucks cheaper a year.
Let's convert this number to kiloWatts by dividing by 1000, to get 0.28 kiloWatts.
These devices, that have been on for 24 hours, have consumed
0.28 Watts × 24 hours = 6.72 kWh (kiloWatt-hour) of energy.
Finally, since energy costs you $0.15/kiloWatt-hour, these devices have costed you:
6.72 kWh × $0.15f/kWh = $1.01 a day * 365 days = $368.65 to run a GPU for a year
Which gives you 700Kh?
Now instead you buy 10 of the USBs and run them LTC only and you have spent $980
Let's say they use 20 watts a day ($0.07 a day) or $25 a year to run
$980 + 25 = $1005 for 700Kh is total operating for a year for these.
A GPU of the 7970 type is $440 plus the $368 for electricity is $808 cost to operate for a year.
Both the GPU and the USB Dual miners require a computer so we wont add those in and we wont add in the $80 for a good USB hub to run 10 of them.
I am not going to argue that its cheaper or roughly the same price to build a rig with USBs then GPUs. But
there are two other points to consider.
They are:
1. The cost of cooling.
2. The scalability of the setup.
So I live in Texas and A/C is almost worshiped more then the Good Lord. I have 9 cards. They push out a
decent amount of BTU. In fact a 5000 BTU window unit would have a hard to keeping up. So I got a 12,000 BTU
standing unit. So it runs roughly 1/10th (or a little less) the total time in a 24 hour period. These little
USB guys do get hot but the total BTU will probably be much less then there GPU equivalent. Thus there is
some power saved by cooling.
Of course the amount of power saved probably isn't $100 a year. Well depending on the size. Which brings me
to the second point. Scalability.(I should try to caculated my average cooling costs and post
them in another forum as here probably wouldn't be a good place for that)
So I mentioned I have 9 cards. I currently have 40 amps. Or two 12Gauge cables connecting two 20AMP breakers
to two 15 AMP wall sockets. So actually I only have 30 AMPs. Its a iffy buisness when you start pushing
more then 15 AMPs. And the moment you want a rig or rigs that have more then say 4/5 cards and you don't
live in a DataCenter you are going to run into problems. My 9 cards (and a case fan and an butterfly 60Gh miner)
is pushing nearly 20 total amps! Then there is my standing 12,000 BTU AC. The setup has space for 7 more cards
but not enough power. The amount of work/money involved needs to be caculated as well. 12Gauge wire isn't cheap.
All this to say. If I want to expand my rig without buying office space (with 4 other mining hobbiest in my
area, yeah we are currently looking into that) I am going to have to spend a lot more money and time putting
new sockets in my walls. But with this I can expand to much faster hashing rates.
Side Note: With the operating costs much lower my investiment can operate longer before it losses is
profitablity. What I mean to say is with ASICs around the corner in the next year for scypt my 9 cards are
going to become obsolete sooner then those USB sticks.
And sorry for the long post. *sigh*
P.S: I paid for 3 of these today. I will post back here again with more info like how fast I get tracking info and when I actually get the products And how fast 3 mine together not just one.
Thanks for your long post! You just said what I want to say. Power supply is always the limitation of mining operation. "Green" ASIC chip helps a lot to reduce operation cost, especially to serious miner like you.