Greetings! This thread is for support and information about the BFx2 USB stick miner that will be available shortly. It looks like this:





Specs:
2x Bitfury gen 1
~4GH/s depending on how hot you want to run
Power draw of ~1000mA
FTDI USB-SPI bridge
cgminer and bfgminer support in main branches

Resellers:

https://bitcointalk.org/index.php?topic=547303

www.cryptoware.co.uk (defunct, but still available from the forums)

Also, check eBay, there are lots for sale there.

Check out this video:

https://www.youtube.com/watch?v=g3A6GdWrOSs

(I am not affiliated with the video producer)

Linux cgminer support:

Since support for this miner is in the master cgminer branch, getting a Linux binary is as easy as downloading the latest cgminer-<version>-x86_64-built.tar.bz2 file from:

http://ck.kolivas.org/apps/cgminer/

Please read and follow the instructions in the ASIC-README file provided by cgminer. It will help you get your Linux set up to use USB based miners.

If anyone needs a 32-bit Linux binary that will work on a recent Ubuntu (tested on 13.10), reply to this message and I'll post one.

Since people will ask what hashrates these get, I've been running mine at bxm bits 54, but they are engineering samples and not final units. Nonetheless this is what I have:

THey can be overclocked to 5 giga hash,

at 0.165 bitcoins they are priced at $95, which is a fair price

That is my site, we are the Asian reseller  

In stock today and we are shipping immediately.

There has been a request to discuss over clocking these boards. I'm the designer of the board, and these are my thoughts on over clocking, but of course your results will vary and you could end up destroying your boards! I don't recommend doing any over clocking, but since Bitcoin is about experimentation, here goes nothing!

These boards were designed to run at 4GH/s with ambient cooling on the heat sink. This allows them to run at <500mA and thus be USB2 compatible. When over clocking a Bitfury based design, heat is your enemy, you will need active cooling from a fan if you over clock these boards.

With the way Bitfury chips are designed, heat really is the enemy. As the chips heat up, they slow down and also start producing hardware errors. Software over clocking will increase the heat dissipated by the chip and thus can actually produce worse results. Same with increasing the core voltage.

Software over clocking:
The current cgminer release supports software over clocking with the --bxm-bits=XX command line parameter. Non-over clocked optimal is 53 or 54. However, you can go to 55 or 56 if you introduce active cooling.

Increasing the core voltage:
In order to get the Bitfury chips to run stably at higher clock values increasing the core voltage is necessary. Again, the boards were designed to get to 4GH/s so the core voltage was chosen accordingly. Increasing the core voltage will really increase the heat output. Cooling the boards with a fan is absolutely necessary.

The core voltage is set by three resistors, but the only one you want to change is R6. It is right in the middle of this picture:


As built R6 = 499 ohm, to increase the core voltage use a larger value, but don't go above about 1.5k. You'll need a 0805 surface mount resistor. To measure the core voltage the chips are seeing, measure across the decoupling capacitors that surround the Bitfury chips. Explaining how to desolder/solder a resistor is way beyond the scope of the forum ;-)

Active cooling
I thought it might be fun to add a 40mm fan to the heatsink:



To do so, find a 40mm fan and screw it to the heat sink. Then solder the wires to the USB connector as indicated above.

Anyways, have fun hacking up my creation!

I think your instructions are overly complex and I highly recommend people just use the cgminer way. There is but one step to setting up on permissions on ubuntu (as per  the README):

Any word yet on the bfgminer support?

sorry for probably stupid question, but would like to be sure:
does it work with stratum+tcp pools?