Bitcoin mining with USB Block eruptor

[drdops]

Hello all,
Been reading through a lot of the posts checking out the different group buys for mining hardware ( not realising I couldnt ask questions in the threads I was reading)- so here's a few newbie questions...
There is a group buy (by member canaryinthemine) where he's selling the asic miner USB devices for around 1 BTC. I was thinking of buying 10 . Am I correct that these are 333mh/s each- so 10 would be 3330 mh/s approx.   Can someone correct me if Im not understanding correctly- but I put 3330 into a mining calculator at current difficulty and it came out around 7 dollars per  day basically taking over 150 days to make the money back on the hardware ( assuming no change in difficulty-some chance!). can someone tell me why anyone is buying them-at least in bulk- I can understand 1 or 2 to play around?
Also- what type of hardware setup would be required to run lets say 10 of them stacked together? are there special types of USB hubs for them. Dont know much about the raspberry pi-can that run 10 of them? Any info appreciated.

[TheSpiral]

They will never make their return on investment if you take into consideration difficulty increases.
As for USB Hubs, any powered USB Hub should run multiples easily, and the Raspberry Pi should detect them all from a powered hub.
Although, they're undeniably pretty. (https://i.imgur.com/BJCe9a0.jpg)

EDIT: Calculator taking difficulty into the calculation: http://www.coinish.com/calc/   Click Expert, put in the 333 MH/s

[hookthem]

They will never make their return on investment if you take into consideration difficulty increases.
As for USB Hubs, any powered USB Hub should run multiples easily, and the Raspberry Pi should detect them all from a powered hub.
Although, they're undeniably pretty. (https://i.imgur.com/BJCe9a0.jpg)

EDIT: Calculator taking difficulty into the calculation: http://www.coinish.com/calc/   Click Expert, put in the 333 MH/s

What power requirement did you use in your calculation?

[TheSpiral]

They will never make their return on investment if you take into consideration difficulty increases.
As for USB Hubs, any powered USB Hub should run multiples easily, and the Raspberry Pi should detect them all from a powered hub.
Although, they're undeniably pretty. (https://i.imgur.com/BJCe9a0.jpg)

EDIT: Calculator taking difficulty into the calculation: http://www.coinish.com/calc/   Click Expert, put in the 333 MH/s

What power requirement did you use in your calculation?

I just use 0, since they're just bus-powered (although technically that still draws power). Even at 0, you'll have bad results.

[yasin404]

Hello all,
Been reading through a lot of the posts checking out the different group buys for mining hardware ( not realising I couldnt ask questions in the threads I was reading)- so here's a few newbie questions...
There is a group buy (by member canaryinthemine) where he's selling the asic miner USB devices for around 1 BTC. I was thinking of buying 10 . Am I correct that these are 333mh/s each- so 10 would be 3330 mh/s approx.   Can someone correct me if Im not understanding correctly- but I put 3330 into a mining calculator at current difficulty and it came out around 7 dollars per  day basically taking over 150 days to make the money back on the hardware ( assuming no change in difficulty-some chance!). can someone tell me why anyone is buying them-at least in bulk- I can understand 1 or 2 to play around?
Also- what type of hardware setup would be required to run lets say 10 of them stacked together? are there special types of USB hubs for them. Dont know much about the raspberry pi-can that run 10 of them? Any info appreciated.

Try this calc http://www.alloscomp.com/bitcoin/calculator

[J35st3r]

They will never make their return on investment if you take into consideration difficulty increases.
As for USB Hubs, any powered USB Hub should run multiples easily, and the Raspberry Pi should detect them all from a powered hub.
Although, they're undeniably pretty. (https://i.imgur.com/BJCe9a0.jpg)

EDIT: Calculator taking difficulty into the calculation: http://www.coinish.com/calc/   Click Expert, put in the 333 MH/s

Not all hubs. USB3 hubs have been reported not to work with the rpi, and some are underpowered for multiple devices. Just trawl thru the forums for info, a good start is https://bitcointalk.org/index.php?topic=220905.0

Otherwise I agree completely. You won't get your btc back, but they may be fun to play with. And that calculator is one of the best IMHO.

[drdops]

Had a look at that calculator. thanks.
It calculates a 9% reduction per week making the ROI take over 3000 days? Is this reduction based on increasing difficulty? How accurate is that-I mean it doesn't seem like the difficulty is increasing at that rate?

[TheSpiral]

Had a look at that calculator. thanks.
It calculates a 9% reduction per week making the ROI take over 3000 days? Is this reduction based on increasing difficulty? How accurate is that-I mean it doesn't seem like the difficulty is increasing at that rate?

Well, obviously it doesn't change difficulty every day, it does increase every few days though, the calc averages it out to a per-day basis. It's an estimate, but accurate within a certain range.
Resource: http://dot-bit.org/tools/nextDifficulty.php
It will show the last/current/next difficulty of BitCoin (And Namecoin). Also an estimation. Other estimation:
http://bitcoindifficulty.com/