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Re: BFL Single and BFL mini-rig seems to have inferior performance
by
bitfury
on 03/07/2012, 00:21:23 UTC
Quote from: Gomeler on July 02, 2012, 04:27:15 PM
Quote from: bitfury on July 01, 2012, 02:48:56 PM
Quote from: BlackPrapor on July 01, 2012, 02:11:46 PM
Maybe he realized that there is no way to compete with BFL and wants to get a job there, by showing how 'smart' he is. Otherwise, he'd just make something better himself Smiley

Well. I don't need job with them, but I may sell to them solution of course. Right now they have more than enough money just to buy some know-hows about sha256. And looking at their hash-rates I clearly see that they need it :-)

As for Spartan solution - it is already fastest, and if yohan's prices for board combined with my bitstream price per Mh/s would be $0.53 / Mh/s for FPGA (1200 Mh/s for $640). This already beats BFL prices. If my licensing per-spartan would be applicable ($25 per chip) - then it would be 1200 Mh/s for $740 - $0.616 - again beats BFL. But - yohan prefers 840 Mh/s :-) While our capabilities do not allow to deploy quickly and cheap solutions.

For ASIC solution it is tougher - because this sets stakes higher. And I don't like to happen competing with phantom like it was with 20 W / 1050 Gh/s single... Trying like crazy getting 500 Mh/s from single Spartan :-) And then seeing that no magic was there, just some marketing fraud. I think they did it with this intention as well, to make others spending time trying to compete with the thing you can't :-) And then simply say "oops" - it is 80 W but not 20 W :-) Sorry - this is the thing that I won't forget :-) Quite happy that mini-rig was done differently. :-)


If I recall, don't you run your Spartan6s at higher voltages to achieve the MH/s that you are with your design? I imagine you'd hit the same problem that the tricone design is hitting with sagging voltages on boards that don't feed a slightly higher core voltage.

About board voltage - yes - 1.3 V, and 1.26 V on chip. We have board in production with separate power supplies and LVDS high precision clock supplied based on SI5338A external PLL. It may give superior performance to Spartan internal clock generators.

2 mrb: thanks for your input. 66 W per single means about 33 W per chip and including COP of system it is probably 26-28 W per chip (I expect 12 V -> 1.1 system should have COP about 80-85%).