Can you please tell me how much do you estimate this setup cost you?
It's quite magnificient and quite a job!
Cost for you to build this system today:
16 X6500s at $550
each: $8800
Power supply (I used
this one): $65
4 120 mm fans at $15 each: $60
Various Molex splitters and adapters: $20
16 USB cables: $50
USB hubs: $30
Total:
$9025 / 4.2 GH/s or 2.12 $/MH
A lot of those extra things you probably have sitting around already, or you could find better deals.
The next price break above that is at
25 units. You could still run that many boards off of a single supply (400W) so your overhead cost would only be slightly higher.
25 X6500s at $535
each: $13,375
Power supply: $65
Fans: $90
Various Molex splitters and adapters: $30
25 USB cables: $75
USB hubs: $40
Total:
$13,675 / 6.6 GH/s or 2.05 $/MH
You will also need a host computer to run the system, but you most likely already have that and the performance requirements on that computer are quite low.
Note that those $/MH are based on 266 MH/s for each X6500. I have every reason to believe that we will reach higher hashrates with improvements to the software and firmware in the future.
This is fascinating to see someone actually do an FPGA farm in scale. I could not stomach the upfront capital cost needed to replicate my 18,000 MH/s. My my rough math, it would cost $35,000+ to get to that speed!
Now clearly cost savings would start to offset the capital cost, but that is a loooong payback. Also, the salvage value is much higher on GPU's, which has a huge impact on the NPV calculation.
I have invested $12,500 into my operation, and get 18,000 MH/s. $.69/MH. Pretty damn good!