Interesting idea ...
By the way - bfgminer will start by default with 50 bits - as that's the one that is safely within the USB2.0 specs.
Our observations show that everything would most likely work just fine even at 52-54 bits, but since that would be pushing the boundaries you can do your own experiments and find out how much could your PC or hub tolerate. Hence the command-line parameter with the bits.
Keep in mind that the command-line parameter will set the default bits for all Bitfury chips. After you start bfgminer you can go to the device management and change the bits for each individual device - that way if you have devices or ports that tolerate a bit more you can set a different speed for just those individual devices. You can even set a different speed for every single one.
Another observation - it appears that bfgminer is able to squeeze out a few extra gigahashes than cgminer
Below is the same stats from bitminter of the device I've been testing for the last few days - running at 54 bits:
No. Completed Duration Total Ghps Difficulty Your score Total score Your work Total work My % My GH
19023 10/26/2013 5:11 0h 56m 198,763.04 390,928,787 0.00000482 0.40107124 1,885 156,790,293 0.0000120224 2.3896
19022 10/26/2013 4:14 0h 56m 198,062.58 390,928,787 0.00000489 0.40119134 1,912 156,837,243 0.0000121910 2.4146
19021 10/26/2013 3:17 0h 55m 199,040.56 390,928,787 0.00000489 0.40010072 1,886 154,460,358 0.0000122103 2.4303
19020 10/26/2013 2:21 0h 38m 199,221.31 267,731,249 0.00000476 0.40125034 1,274 107,427,255 0.0000118592 2.3626
19019 10/26/2013 1:42 0h 38m 199,667.36 267,731,249 0.00000492 0.4028433 1,316 107,853,739 0.0000122017 2.4363
19018 10/26/2013 1:03 0h 39m 197,912.16 267,731,249 0.00000485 0.40480966 1,299 108,380,195 0.0000119856 2.3721
19017 10/26/2013 0:24 0h 38m 198,882.46 267,731,249 0.00000479 0.40074082 1,283 107,290,841 0.0000119582 2.3783
1901610/25/2013 23:45 0h 39m 197,049.78 267,731,249 0.00000477 0.40218894 1,277 107,678,548 0.0000118594 2.3369
1901510/25/2013 23:05 0h 38m 201,886.68 267,731,249 0.00000465 0.40468739 1,245 108,347,460 0.0000114908 2.3198
1901410/25/2013 22:27 0h 38m 196,948.57 267,731,249 0.00000459 0.4002696 1,229 107,164,680 0.0000114683 2.2587
1901310/25/2013 21:47 0h 38m 201,282.27 267,731,249 0.00000468 0.40032505 1,253 107,179,526 0.0000116907 2.3531
1901210/25/2013 21:09 0h 38m 198,070.43 267,731,249 0.00000507 0.40065487 1,357 107,267,829 0.0000126506 2.5057
1901110/25/2013 20:30 0h 38m 200,747.95 267,731,249 0.00000489 0.40153187 1,308 107,502,630 0.0000121671 2.4425
1901010/25/2013 19:51 0h 38m 199,415.63 267,731,249 0.00000492 0.4014683 1,316 107,485,609 0.0000122435 2.4415
1900910/25/2013 19:12 0h 39m 198,747.57 267,731,249 0.00000469 0.40513568 1,255 108,467,483 0.0000115703 2.2996
1900810/25/2013 18:33 0h 39m 195,373.80 267,731,249 0.00000492 0.40080704 1,316 107,308,570 0.0000122637 2.3960
1900710/25/2013 17:53 0h 39m 195,515.88 267,731,249 0.00000493 0.40109851 1,320 107,386,605 0.0000122920 2.4033
1900610/25/2013 17:14 0h 39m 195,703.41 267,731,249 0.00000496 0.4043765 1,328 108,264,226 0.0000122663 2.4006
1900510/25/2013 16:34 0h 39m 195,852.02 267,731,249 0.00000487 0.40298034 1,304 107,890,430 0.0000120863 2.3671
1900410/25/2013 15:54 0h 39m 193,534.11 267,731,249 0.00000502 0.40023075 1,345 107,154,279 0.0000125520 2.4292
2.3869
