Sound great to me! Hopefully MasterCard and others will follow suit.

I do hope that your friend who bought the miners reported the issue with them to the seller and eBay (though the seller may have been who intentionally did the infection).

What do they have in common - nothing.
However, as in many industries, blockchain tech can be used to verify the source/owner of something. In this case say you make a 3D model of a specific widget and charge for the STL file to it. Blockchain could be used to verify who created the file, owns the rights to it and that the file is unchanged from when it was entered into the blockchain tracking system.

Yes a private database is able to do the same thing but usually does not allow the Public to query it. A distributed (Public) Ledger does let the 3rd parties query it. The only remaining question would be who runs the chain.

Can you run them together? Yes. Should you do that? Not really. Just as with the A721/741 series, the 821 and 841 should have separate controllers.
One reason deals with firmware updates, an update runs on ALL miners attached to a controller and the MM updates are specific to miner type. An 821 does not like thinking it just became an 841... (been there, done that)

The difference is that a neutral (common) is intended to carry power and a ground is intended only for safety in the event a line contacts a metal chassis. Yes both tie together inside the panel but that must be the only place they are connected. It is what makes a neutral, well, neutral with only a small voltage difference (that depends on the load & wire size) between the other end of the wire and any ground you find.

As lightfoot said, older electric dryers and ovens often used to improperly use the ground to give 110v to timer motors & light bulbs. It was only allowed by some local electric codes  because said loads draw very little current so *in theory* the combined neutral/chassis ground *should* have very little voltage difference on it referenced to any nearby water pipes or any other grounded metal.

Of course *in theory* means that it is not always the case so a dedicated neutral is now mandated when a high line system needs a neutral connection to provide lower control or aux power.

Methinks it's Inno's idea of a soft-start circuit? 

Ja or at least continue it here in the existing thread about it.
It has become seriously OT.

^^ Posted to Discord for him to pop in on it. He has talked about this several times there.

No matter what given that all claim to have many many users, why is it so hard for someone - anyone - that uses 3rd party firmware to post proof it has found a BTC block? Most GUI's have a spot for it and a record of blocks found since last reboot  is part of the API so can be checked even outside of the miner GUI.

On the pool side of things, when shares are sent/received information about the miner is provided as well to let the pool/miner work together. Plus when a block is found the block header generated includes information about the actual individual miner that found it. That info is more than just 'running cgminer vxxx'' and is easily logged by a pool if they care to keep detailed logs, for a start is part of the header from the block I found on Dec 16. From what Kano has said, a pool operator can extract more information as well if they care to. It should be common sense to link together miner data with block header info to track performance metrics.

Since Slush is behind the bOS projects, why not provide simple, verifiable proof the stuff finds blocks? They certainly have a large enough data set to see what miners (or, ahem, large proxy) find blocks and compare that against expected finds vs hashrate. So, if responsible pool operators want verifiable proof firmware works - give it to them.

Oh, their Stratum redeux freely gives a pool, sorry - they call it 'Service' -that info and knowing in-depth what a miner is running and can do is a large part of what it relies on to do the voodoo they plan on it doing.

Then there is #xnsub being part of it... While not an issue per se #xnsub opens up a rather large security hole and exists (so far) only for the benefit of Nicehash and DevFee firmware. It is how NH is able to change work done w/o having to restart a miner. It is also used by DevFee firmware to mine at their payment pools in the background without the miner needing to change pools & restart. Yes a lot of miners support #xnsub and yes BM had to reinstate support for it again after folks bitched about not being able to use their newest miners on NH. That still does not make it a good thing...

Um, look at the Kanopool home page. The ban on 3rd party is in big bold red letters and has been a long standing policy for a few years.
A couple reasons for it:
a. Most violate the CGminers' Open Source license by refusing to provide their source code. If bOS provide their code, fine but that still does not address the next point,

b. Despite many requests for it - NO 3rd party firmware provider has ever given*any* proof that the firmware finds BTC blocks nor given any proof of testing for more than it does not crash but does do what they claim (control of clocking, voltage adj, fans etc)

Do be aware that for several reasons using non-OEM firmware is not allowed here.

Use Braiins as a test, fine, but prolonged usage will get you kicked from the pool.

And just why should anyone care what Bill thinks about CW's claim? (though in this case he is right - CW is a fraud)
As mk4 said, looks like cointelegraph is desperate for 'news' and so are posting clickbait to get eyeballs on their site.

AFAIK, no. Voltage changes require reboots/restart of cgminer though that can all be done via scripts.

Well, post #33 here on page 2 of this thread has a list of all A9 commands.

While you are there, that page also has results of Phil's playing with voltage-level.

Unlike previous Avalons, the 921 does not like using the More Options entry box to change it. Several folks have experimented with different freq, voltage level, voltage level offset, etc with very limited results.

It pretty much only runs in the 2 modes that Canaan gave us.

That's fine and dandy but - if you are the one that solves the block, how are you going to have them divide up the reward? Are you willing to let the folks in the sub-pool keep it all?

Only way is by the 0.1BTC block finder bounty attracting a few very large farms - which is the whole point of the bounty and change in ramp time...
No matter what, anyone who finds a block before the halving gets the bounty.

Not bad at all! Gives me some ideas for what to do with the one that likes to drop a board - same one every time and yes is the middle one as well - every now and then..

That ^^ is a perfect example of a regulator that uses a variac (trade-marked name of one make of variable transformer). FWIW 'variac' has become a generic name for them rather like Kleenex became the generic name for facial tissue.

They do not switch between multiple fixed taps, a servo moves a sliding contact over the exposed windings of the transformer so there is no dropouts during adjustment. Und ja - that is a perfect solution that is usually lower cost vs pure electronic regulation. Their only drawback is that along with slower response time, after many years of use the graphite contact brush will eventually wear out and need replacement. Any 'clicks' you are hearing is usually the raise/lower relays operating to drive the motor that moves the sliding contact arm.

Of course this sorta should have it's own thread but - in reality few folks use AC voltage regulators.

That said, ANY buck-boost transformer that is designed & intended for industrial use (like the ones from Larson) should last for at least several decades even when ran at 100% load. It's just the nature of the beasts.

Consumer types such as this are utter crap! Long long a go I tried a few different types and despite being ran at about 50% of their 'rated 3kw' load all crispy-fried themselves in about 1 month. Upon doing forensics it became obvious why: a. the core is too small causing excessive eddy current loses, b. the wire used in them is far too thin leading to even more losses and the windings getting very hot.

As for regulators: Biggest thing is that they MUST use fully electronic control for adjusting the output voltage (like the Norstar's) or drive a variac to do it. Lower cost tap-switching units cannot be used as they all momentarily drop to 0v out during the switching process. Ja it is only for a few ms but nonetheless it's a safe bet that the miner PSU will have a problem with it and probably trip a reset.

The only place I use a regulator is at home where the line can have substantial sag during the summer. For that I use Cyberpower's line of dual-conversion UPS's that run AC > DC > DC > AC. Their AC power is always derived using a inverter that directly adjusts the voltage (and freq) so there is zero switching time for voltage adjustment or switching to battery when the power drops out.

^^Perhaps.
However I also see  a technical need for less THs per-miner and the resulting less power draw per-machine: namely what happens when a miner goes down.

The fact that 1 miner down can now mean up to what, around 75THs or more lost? On the PSU side, keeping the total output to say (with margin) 1,600w makes it easier and cheaper to make than one that has to pump out 3-4kw. Certainly easier to cool. Those multiple tiny fans scream....

To me, unless you are running several hundred PH or more, I'd much rather have say 20-30THs per miner drawing 1,500w or less. Sure, you need more of them but unless they are uber-reliable like Avalons have historically been then I'd much prefer a miner failure to take out a lower % of the total farm hash rate.

The side benefit is that it keeps power draw to something that a 'home' miner can easily provide if they decide to mine regardless of electric cost.