Quote from: philipma1957 on February 06, 2017, 09:34:48 PM

Quote from: blockchainmines on February 06, 2017, 06:31:27 PM

canaan avalon 741 actual load

So I am trying to justify moving completely away from bitmains S9's and into canaan avalon 741. Yet power is everything in this game. I need numbers. An Avalon 741 is rated at 1150 watts for 7.3TH where an S9 is rated at around 1300W for 13.5Th. Can someone tell me what the 741 is really pulling. It takes 2 741's to get the hashing power 14.6 TH, but now you are at 2300W. That is crazy, 1000 watts more to get the same damn hashing rate as bitmain, really? Huh

I am not looking for cheerleaders on either side but rather the facts that can be backed up.

Thanks!!

simple facts the s9 gets better power results then the avalon 721 or 741

the s9's I owned and still own broke quite a bit.

the r4's get better power results then the avalon 721 or 741
the r4's I own have a bad failure record.

The 3 avalon 721's I own all work.

Last set of facts and these are very important facts
if your power cost is over 10 cents mining sha 256 for btc is not a good idea you should go for alt coins

if your power cost is 8 to 10 cents a kwatt the s9 looks to be the better buy.
if your power cost is 5 to 7 cents a kwatt the s9 or a721/741 are neck and neck
if your power cost is under 5 cents a kwatt the 721/741 is the better choice.

My group's BTC farm consists of 108 x S9-v1s for about 7 months now, and 120 x A721s coming 2 months.
Labrador ISP is using Hydro power so its the "5 cents" range as listed by Phil above.

S9 farm - about 15-20% of the lot gives me a lot of headaches (mostly HW issues, dead boards & controllers) and required 3 x RMAs to get them to behave. I must admit that Bitmain has honored all RMAs but process takes 2-3 weeks each which too long. Every miner down = lost in revenue. Daily farm monitoring is mandatory so my ISP runs a script to scan and pick out S9s that hashes below a threshold and reboots that miner. Last resort, power cycle that is still done manually by on-site engineer or I remotely access the APC Switched PDU system.

A721 farm - after setting and finetuning the controllers (6 x controllers manages 20 x A721s), they rampup fast and hash. About half of them are hashing at near maximum speed (120THs per controller) and the other 3 slightly under 100THs per controller. Still fine-tuning them along the way and no RMAs required yet. Farm management is a breeze because any pool changes is done on 6 x fast controllers, unlike S9s where without a proxy server setup, you basically need to change pool settings on each miner. I dont worry about the A7 farm as much.

Conclusion:
I rather be happy the farm is steadily mining - stable and HW in tip-top condition, than a farm that needs babysitting and headaches all the time but gives me "a few more BTCs because of that a few hundred extra THs" -- BTC$ speak, I rather pay that amount to have a steady farm and a peace of mind.

Eventhough, we go strictly by hash/power ratio => ROI => profitability, I have to add another factor: "hash opportunity lost due to downtime/underhash". At this point, A7s is leading the way in overall efficiency. My group will do a final expansion of the farm from 2PH to about 3.3PH this year (short of buying our own power transformer), likely will use A741s or better, to deliver best overall operating efficiency. If Bitmain can get their quality control improved then we have real case to consider their S10 or whatever, meanwhile full speed ahead because Labrador has a long winter period.

Good mining everyone!