hash rate versus bandwidth

[a.miner]

How does one calculate the bandwitdth required per THash for Stratum and GetBlockTemplate mining protocols?

[Sonny]

No idea about the exact bandwidth usage.

But, it is very low if you set your share difficulty correctly.

[a.miner]

No idea about the exact bandwidth usage.

But, it is very low if you set your share difficulty correctly.

Thank you, Sonny!

How is "share difficulty" different from "current difficulty" on the Bitcoin network?

[Sonny]

No idea about the exact bandwidth usage.

But, it is very low if you set your share difficulty correctly.

Thank you, Sonny!

How is "share difficulty" different from "current difficulty" on the Bitcoin network?

At this moment, the bitcoin difficulty is 2,193,847,870.
If you find a hash below the target (=above the difficulty), you find a block.
The bitcoin difficulty adjusts itself every 2016 blocks, according to the time needed to find the past 2016 blocks.

Of course, it will takes a very long time (probably never ) for one individual to find a block with such a high difficulty, and that's why we join a pool.


For most of the pools, it allows users to manually set their own share difficulty (or it will be set automatically based on that user's hashrate).
If you find a hash above your share difficulty (as low as 1, as high as 1024 atm), you will find a valid share and submit it to the pool. Pools will then pay you for your shares with different payment schemes.
https://bitcoil.co.il/pool_summary.pdf

So, if you set your share difficulty to 1, you will find tons of shares (depends on your hashrate) every second, and will need to submit a lot of data to the pool every second.
If you set your share difficulty to 1024, you will probably not able to find a share in minutes (depends on your hashrate), and you will find your mining revenue fluctuating a lot.

FYR: Suggestion for how to choose a pool difficulty for miners.
https://bitcointalk.org/index.php?topic=274023.0

[a.miner]

Another very informative answer... thanks again, Sonny!

The thread you linked, by ckolivas, is particularly useful.

Okay, if I have this right, then we want to set the share difficulty such that the mining rig is getting, say, 20 hits per minute, which works out to

hit_rate = 20 / 60 = 1 / 3 hits / sec

To make that happen, we have to set the share difficulty to

diff = (2^16 - 1) * 2^208 / 2^256 / hit_rate * hash_rate
     = (2^16 - 1) / 2^48 * 3 * hash_rate
     = 6.985E-10 * hash_rate

which works out to 698.5 per terrahash.  This works out to 1000 per 1.432 terrahash, which is exactly the value given by ckolivas.

Fine.  Now we have our miner going out to the network 20 times per minute to get more work.

How many bytes will be transferred in each direction, every time this happens?

This will be different for Stratum vs. GetBlockTemplate, right?

So what’s the answer in each case?

[Sonny]

Another very informative answer... thanks again, Sonny!

The thread you linked, by ckolivas, is particularly useful.

Okay, if I have this right, then we want to set the share difficulty such that the mining rig is getting, say, 20 hits per minute, which works out to

hit_rate = 20 / 60 = 1 / 3 hits / sec

To make that happen, we have to set the share difficulty to

diff = (2^16 - 1) * 2^208 / 2^256 / hit_rate * hash_rate
     = (2^16 - 1) / 2^48 * 3 * hash_rate
     = 6.985E-10 * hash_rate

which works out to 698.5 per terrahash.  This works out to 1000 per 1.432 terrahash, which is exactly the value given by ckolivas.

Fine.  Now we have our miner going out to the network 20 times per minute to get more work.

No problem.
Yup, your calculation is perfectly right.  

How many bytes will be transferred in each direction, every time this happens?

This will be different for Stratum vs. GetBlockTemplate, right?

So what’s the answer in each case?

Too bad, I have no idea about the exact bandwidth usage.