Avalon 741s

[jbillk]

I have some Avalon 741s.

Anybody know if there is any open source firmware for higher efficiency modes? (frequency/voltage tuning). Seems like Cannon has abandoned them, latest firmware 2017.

I know about the voltage offset option, but does seem to achieve much better efficiency. It would be nice if they had something like the 8 series have.

Its disappointing Cannon haven't continued to develop the firmware. I'm still getting firmware and efficiency upgrades for My 3 year old S9s. I guess they make a good doorstop stop now...

[NotFuzzyWarm]

No matter what you do the A741's will not achieve much better efficiency at reasonable speed. The chips just cannot do it.
That said, the Avalons are high tweakable to get better eff by playing with the voltage, voltage-offset, and freq. Just don't expect any major gains. Folks have already played with those so search for the main Avalon 741 review thread in the Forum to see what they did.

For the most part these days the A7's are really only good as heaters during cold months...

The only reason the s9's are running better today is because BM originally crippled them via their firmware whereas Canaan has always shipped miners with the best tested firmware at the time.

[jbillk]

Thanks,

I'm not to worried about getting good TH, just reduce the high power consumption and noise.

Would be nice if i can run them silently on standard 120V plug. Better than sitting in a box in my basement. Cant even give these away, even with the recent price hike. Where the S9s I can still sell for a decent price. I regret buying these, even though they have ROI'd. I would of been in much better position if i got S9s instead of the Avalons 2 years ago.

[NotFuzzyWarm]

Here the best I got from a 741 that I used to use as a heater in my TV room. The PSU fan is louder than the miner.

Home A741
Single miner, firmware is MM 9211809-b150820
More Options

Code:

--avalon7-voltage-level 8 --avalon7-freq 524 --avalon7-fan 10-40

Results:
 GUI speed  5360.83GHs Kano speed 5.25THs power ~750w from 120V source
 Quiet enough for office or TV room

Code:

    Temp[39]
    TMax[86]
    Fan[2220]
    FanR[29%]
    Vi[1211 1211 1215 1215]
    Vo[4166 4138 4124 4148]
    GHSmm[5902.34]
    WU[75713.21]
    Freq[524.00]

Something to keep in mind is that BM's hash board failure rate is fairly high. For those with many miners it is not uncommon to see a 10-15% failure rate often in less than a year or so. I used to run 16 s9/T9's ranging from batch-1 up to batch 25 (around 3 years ago) and every single one had at least 1 board fail. For the most part Avalons run forever with very few hardware failures reported here in the Forum. I currently run 21 Avalons, most are 841's and 2x 921's. To date only 1 failure and that was a PMU board on a 821  

[jbillk]

Perfect,

@ 750w, you can probably even put 2 on one 120v, 15A circuit. Exactly what I was looking for.

Thanks, ill have to play around with it.

I've had fairly good luck with the S9s, running 6 of them, but probably because a got them used, and they have already been proven reliable by the previous owners. I heard if they fail, it happens fairly early in their lifespan.