Topic: [DeM] Deutsche eMark - DEM - cryptocoin SHA256 POS/POW - page 62. (Read 237668 times)

It's true that my comments apply to a pure POW coin. Since DEM became a hybrid POW / POS, I assume more blocks will be found than would have been the case purely from POW.
Also, ¿ was there was a change in how the core software calculates network hashrate from the old wallet to the new one ?  If so, then it makes no sense to compare these two numbers.

Hi

i found this ..... (with my comments in red)

----------------------------------schnipp----------------------------------------
So, to calculate the average hashrate for a given period, simply:

1) Take the total number of blocks generated for that period (for DEM should be a block every 2 minutes otherwise the difficulty will change in a predifined time)

2) Muliply it by the total number of hash possibilities (2^256 for a 256 bit hash)

3) Divide it by the number of hashes that would be considered "valid" for a block (the target hash value)

The number of valid hashes can be calculated from the difficulty (which should be the same like it mentioned in point 1), which is something that is coded into the protocol.
A good place to start to find out how difficulty is transformed into a target hash value would be: https://github.com/bitcoin/bitcoin/blob/ca1913e8f64fc245157b008d6b37160306aa1d83/src/miner.cpp
Just search for "target".

So every time a block is found (and this should be around 2 minutes) and the difficulty is not changed i can calculate very accurate the nethashrate.
How accurate and how responsive   this calculation is   due to hooping miners (with high hashrates) depends of the length of the period you choose for the calculation.

Just in mind only valid for POW-Coins

Back to the problem:
If i find 3 pools telling me the net hashrate is  39 Thashes (at a given time and all with the same number)
One pool has 1 Thash
second has 4 Thash
third has 8 Thash

and a fourth  pool has 0,5 Thash and telling me the nethashrate is only 6 Thash
there should be something wrong with that pool.
15 Minutes later the numbers changed but in the same relations.

Keep in mind the first three pools are using the old DEM-Wallet and the fourth pool the new DEM-Wallet

Have a nice day

The block time is only a _target_ block time, it's what we want to achieve, on average. But achieving the desired difficulty target with a hashing function is a Poisson random process, which means you might find the desired result in less time or more time than the desired 2 minutes. Only if hashrate and difficulty are well matched, then, in the long run the average of the block times will be 2 minutes.

In a pure POW coin (like Bitcoin for example), difficulty adjust every so many blocks. (In bitcoins, its every 2016  blocks; if blocks come out ona average every 10 minutes, that will be 2 weeks). But if  blocks have been coming out faster than every 10 minutes, then difficulty will be increased by the difficulty adjustment algorithm to slow down the rate of production. If it took longer than 2 weeks to validate the 2016 blocks then difficulty will be lowered to speed up production.

No coin controls its network hashrate (Just look at the problem of multipools suddenly joining and then leaving coin networks). The network hash rate depends on who is mining and how powerful their mining equipment is. People can point their mining rigs at a different coin in an instant!
The only thing a coin network can set and control is the difficulty factor. Most POW coins have switched to much more responsive algorithms to adjust for more drastic hash rate variations than the original bitcoin algorithm could ever handle. (These algos go by names like Kimoto's Gravity Well, Dark Gravity Wave, DigiShield, Delta, etc.) So the difficulty factor is adjusted in these newer algos sometimes as often as every block, but it is always the difficulty factor being set in response to the observed hashrate.

The equation governing this relationship is:

     Hash Rate (hashes / second) = Difficulty (hashes / nonce) x [blocks_found / blocks_expected] x [size of nonce space (nonces) / target block time (seconds) ]

The size of nonce space is 2^32 = 4 294 967 296 (nonces) and target block time for DEM is 120 seconds, to equal DEM's Constant
C = 35 791 394. 13 (nonces/ second) or as Rumhocker says, about 35.8 MegaNonces/second

So let's say a real time hour has gone by, and only 20 DEM blocks have been found in that hour. If the difficulty factor has remained constant during this time, then the Hash Rate can be found with the above equation. Once you know the "effective" hash rate for this hour-long period, then you can use it to set what will be a correct difficulty factor to match the observed hash rate.

For a concrete example, POW difficulty on DEM is now:  1 673 882.67  (hashes/nonce)
If we apply this to the above hypothetical situation,
1 673 882 .67 (hashes / nonce) x [20/30] x 35 791 394 .13 (nonces/ second) = 39 . 940 396 Tera Hashes / Second
Once you know this "effective" hash rate during that hour, now you can find the difficulty factor that will balance this hashrate to produce, on average, a 2 minute block time. (Note that since we want blocks_found = blocks_expected, so that term = 1)
39.94 (TH/s) / 35.8 MegaNonces/second = 1 115 642.4 (hashes / nonce)
Which makes sense ... the difficulty is lowered, because too few blocks were found.

DEM wallet at crypsty  why is still im out

@phatkiller  thx for great info phat. After I saw your post I thought maybe I should get my couple miners out and give it a try. I gave werming pool  a try, got lucky and found a block. I was the only miner there lol. Immer gerade aus   always going straight ahead.

PS: I'm staking later today and will transmit some thankfulness to your address 

no, the nethashrate is not necessary for building a new block and is not known.


Yes, the difficulty is given in the last block for the next block and fix for the next 2 minutes.
The nethashrate is calculated from the difficulty.

estimated hash rate ≈ Difficulty * 4295032833.0 / 120
if Diff = 1000000 ->  Nethashrate ≈ 35 THs 

BUT THIS IS ONLY FOR POW WITHOUT POS

POS coins has a less mininghashrate by miners, (eMark at this time ca. 1/5)
eMark calculate the nethashrate like Novacoin.
https://github.com/novacoin-project/novacoin/blob/master/src/rpcblockchain.cpp#L50
I think this would be the best way to estimate the hashrate.

The Block time is 2 minutes ! So every 2 minutes the chain (for all on the right branch)is synced. So it is clear to me that every 2 minutes the nethashrate is known to everybody synced to the chain (who is not will geht the next block an orphan block).
Because the difficulty is dependent to the nethashrate (blocks have to be finished max every 2 minutes) the nethashrate has to be known to everybody working on the blockchain.

have a nice day

DEM Pool List

http://coinz.at/DEM/
Currently down usually has highest Hashrate of the publicly available pools. I've mined ~100 DEM here.

http://dem.suprnova.cc
Good pool sitting at about 3 - 5 th/s right now.  I've mined about ~1000 DEM here.

http://dem.gcpool.eu
Haven't had the chance to mine here yet low hashrate right around 400 gh/s right now. I think glen123 owns this pool.

http://miner-control.de:8000
This is where I've mined most of my DEM (~5500 DEM) usually sits between 3 - 5 th/s

http://mining.securepayment.cc/pools/emark/
This is a pooled SOLO mine.  Basically if you discover the block you receive full reward minus 3% fee I mined exactly 3 blocks for a total of 145.5 DEM

http://dem.werming.com/
Haven't had the chance to mine here yet low hashrate right around 1 gh/s right now.

http://dem.ispace.co.uk/coindetails/?coin=dem
Great pooled I've mined a few coins on here.

There used to be two others but i think they are gone if i find the URLs i'll post em.

Market List

https://www.cryptsy.com/markets/view/DEM_BTC

Mixed feelings about cryptsy.  I love that they support so many altcoins but this wallet has been in maintenance forever.  They've even stopped
making excuses as to why the wallet isn't working all they say now is that its in maintenance.

https://www.cryptopia.co.nz/Exchange?market=DEM_BTC
Low volume, I've succesfully traded on here without a problem cant complain about the exchange side of things but as far as the mining side ........

https://yobit.net/en/trade/DEM/BTC
Just recently added DEM.  Never traded on here

Final market is coins-e I wont provide link DO NOT trade there as they are holding 7k+ DEM of mine hostage and refuse to release it or even respond in a timely fashion to my emails/support tickets.

Node List
addnode=85.214.246.63
addnode=95.116.228.43
addnode=144.76.238.2
addnode=37.120.176.118
addnode=108.61.10.90
addnode=216.38.34.211
addnode=173.65.129.85
addnode=5.147.116.112
addnode=70.189.142.25
addnode=70.168.53.153
addnode=93.113.101.229
addnode=91.65.72.30
addnode=176.120.166.167
addnode=81.132.37.244
addnode=88.156.95.235

Links

http://deutsche-emark.org- Main DEM website
http://blockexplorer.deutsche-emark.org/ - Official block explorer
http://forum.deutsche-emark.org/ - Official Forum (not in english)
https://github.com/emarkproject/eMark - Official Github download the current version here v1.3.2 at the time i wrote this.

If any of this was useful and you want to hook me up:
DEM NLzuyY1fiTKVK8W2DCTnMn3ntWLvxPCPfP
BTC 1LPXxATniuiTgRaqR6foQkDBPkAv4Kf6RA

In general, pools know their own hashrate quite accurately. I don't know exactly how the DEM core software is calculating the net-hash-rate, but it must be using a certain number "x" of blocks (would have to look at the code to see what "x" is) to determine an ellapsed time which it uses to derive the net-hash-rate over that period of time.
In reality, over any length of time the actual hash rate powering the network can vary up or down very substantially, so that at any particular point in time, the real number of hashes-per-second can be quite different than the number reported as net-hash-rate by the DEM core software (wallet).
So it's not surprising that a pool might know itself to have a higher hash rate than the total net-hash-rate _reported_ by the core software.

You could think of it this way: the pool reports its own instantaneous hash rate, and the wallet reports the average net-hash-rate over a longer period of time.  So the instantaneous hash rate of a pool could exceed the net-hash-rate reported by the DEM core wallet, particularly if a few large rigs very recently joined the pool.

If those rigs stay on the DEM network, eventually the core DEM wallet will reflect that increased hash rate too, but it will lag the pool's knowledge; the pool is the first to know about increased hash rate, because it actually has to give work to the miners; the DEM wallet is only aware of blocks being found, and once the blocks are found then it can calculate how much hashrate was on the network to account for the blocks found over that period of time.

please read this for bitcoin hashrate
https://en.bitcoin.it/wiki/Difficulty


estimated hash rate = Difficulty * 4295032833.0 / 600
Difficulty = 600 / 4295032833.0 * estimated hash rate (hash/s)

eMark have 120s Block time. So change 600 to 120 and test

just to inform :

working on pool. restart in est . 1 h

Coinz.at is deceased (DEAD) for a couple of days

Just again for info



here are three mining pools (with my comments)




coinz.at                            pool very stable but sometimes web-interface is slow (sometimes not available for days !!)
                                       ----> the most miners

dem.suprnova.cc                pool very stable and responsive 
                                       ----> only a few miners

dem.gcpool.eu                    small pool very stable very responsive admin (sometimes a lot orphan blocks --> under investigation)
                                        ----> only one or two miners

with the  parameter : "load-balance" : true, in cgminer.conf you can send shares to all at the same time with one miner.
if one pool fails, this part will switch to the remaining pools.

Have a nice day

yes that works fine - sent a bit of hash as a test - all good


Cheers - usukan

aha - cool thanks

https://dem.suprnova.cc/

am I blind or missing something - can't find DEM here?

https://www.suprnova.cc/

root@gcpool:~/dem13/src# ./eMarkd getmininginfo
{
    "blocks" : 587958,
    "currentblocksize" : 1000,
    "currentblocktx" : 0,
    "difficulty" : {
        "proof-of-work" : 850944.90584612,
        "proof-of-stake" : 0.04090939,
        "search-interval" : 0
    },
    "blockvalue" : 50000000,
    "netmhashps" : 4643939.69670508,
    "netstakeweight" : 1479827.13918903,
    "errors" : "",
    "pooledtx" : 0,
    "stakeweight" : {
        "minimum" : 0,
        "maximum" : 0,
        "combined" : 0
    },
    "stakeinterest" : 38000,
    "testnet" : false

https://github.com/emarkproject/eMark/blob/master/src/rpcblockchain.cpp#L54

will change from 30 to 120

just making backup and recompile


gimme a sec

You are right, i think i made a mistake.
i will take a look at it on weekend.