Re: 1GH/s, 20w, $700 (was $500) — Butterflylabs, is it for real? (Part 2)
I just ran some numbers for Inaba's Single @ https://eclipsemc.com/mw.php?key=196e69b1afe10927460b22a8de1c0d:
3:23pm CST: 65612 shares
12:08am CST: 70949 shares (8h45m later)
So the average hashrate during that 8h45m period was:
70949-65612 = 5337 shares in 31500 seconds (8h45m)
5337 shares * 2^32 hashes/share is 2.29e13 hashes
2.29e13 hashes / 31500s = 727Mhps
Not too bad, but still 13% lower than the advertised specs of 832Mhps.
3:23pm CST: 65612 shares
12:08am CST: 70949 shares (8h45m later)
So the average hashrate during that 8h45m period was:
70949-65612 = 5337 shares in 31500 seconds (8h45m)
5337 shares * 2^32 hashes/share is 2.29e13 hashes
2.29e13 hashes / 31500s = 727Mhps
Not too bad, but still 13% lower than the advertised specs of 832Mhps.
Here's another numbers run, for a 15 hour period to 15:06 CST today. Inaba mentioned there are some issues with his unit that are causing throttling.
@Inaba, have you had a chance to try the ufasoft miner to see if the unit behaves the same? It might provide clues on whether this is a cgminer-only issue, or if it is a fundamental issue with the unit.
@kano, you had mentioned earlier that you were doing some work on icarus support in cgminer; have you seen anything in the code that might suggest a reason for the observed throttling behavior?
start: 00:08CST, shares 70949
end: 15:06CST, shares 79630
So we have:
15:06 - 00:08 = 14h58m = 53880s
79630 - 70949 = 8681 shares
8681 shares * 2^32 hashes per share = 3.73e13 hashes
3.73e13 hashes / 53880s = 692Mhps
Another numbers run for the 10h39m period ending at 1:45am CST; average hashrate continues to drop:
start: 15:06CST (yesterday), shares 79630
end: 1:45CST (today), shares 85418
So:
1:45am - 15:06pm = 10h39m = 38340s
85418 - 79630 = 5788 shares
5788 shares * 2^32 hashes per share = 2.49e13 hashes
2.49e13 hashes / 38340s = 648Mhps