Why is my p2pool share not payed out?

Question

I'm mining Litecoins in the q30.qhor.net P2Pool node at a current rate of around 75 kH/s.

I've been reading that decentralized p2pool mining differs a bit from centralized mining pools, e.g. that you only get paid out when a block is solved successfully.

Now, I'm mining for about 8h now in this p2pool and during that time 3 blocks were solved:

Block   Time                            Luck
409925  Tue, 20 Aug 2013 17:09:16 GMT   155.4%
409848  Tue, 20 Aug 2013 14:02:12 GMT   95.1%
409784  Tue, 20 Aug 2013 12:07:41 GMT   165.1%

That means, some payouts occured during that time. I checked some of the other addresses, they really got instant payouts. But I didn't.

Address                             Hash Rate   Stale   Amount (LTC)
LV6GjHN8...someltcaddress..aWdKZ2g  2.93MH/s    4.36%   0.21685736
LWoKVQ8y...someltcaddress..2dm5FqL  2.44MH/s    5.12%   0.22766967
LedmP6yA...someltcaddress..hGBdLHW  1.97MH/s    7.02%   0.13804534
...
LUj1UAKL...myaddresshere...jWYAPA9  77.8kH/s    1.69%   -

I'm using pool's cpuminer 2.3.2 and see a lot of accepted shares.

 $ ./minerd --version
cpuminer 2.3.2
libcurl/7.31.0 OpenSSL/1.0.1c zlib/1.2.8
 $ ./minerd -a scrypt -r 1 -t 12 -s 6 -o http://q30.qhor.net:9327 -O LUj1UAKL...myaddresshere...jWYAPA9+0.00001800:1
...
[2013-08-20 20:57:05] thread 1: 168 hashes, 6.48 khash/s
[2013-08-20 20:57:05] accepted: 4270/4396 (97.13%), 76.76 khash/s (yay!!!)
[2013-08-20 20:57:05] thread 9: 4116 hashes, 6.41 khash/s
[2013-08-20 20:57:05] accepted: 4271/4397 (97.13%), 76.76 khash/s (yay!!!)
[2013-08-20 20:57:06] thread 2: 7452 hashes, 6.47 khash/s
[2013-08-20 20:57:06] accepted: 4272/4398 (97.14%), 76.76 khash/s (yay!!!)

But I did not get any payout, yet. Why?

Answer 1

The answer is hidden in this forum post here.

"You have the same problem that is common in P2Pool threads, your miner is (relatively) slow compared to the size of the pool, as such you are not solving the required 1 P2Pool share every 24 hours (not the work your miner is submitting). You will get paid when your miner solves a share with a difficulty greater than the current P2Pool Share difficulty (see the website), this is currently about 1.320658 (or 87.4k in CGMiner speak)."

The PPLNS payment system is not to be considered as the best for slow hash rate miners. To get payouts, you need to:

1. solve at least one hash every 24h hours which is higher than the p2pool share difficulty = gets at least one payout each day.
2. solve at least one hash within the window of the current block with a difficulty higher than the p2pool share difficulty = gets at least one payout each block.
3. check if your p2pool server avoids dust payments, meaning that very small payments are hold back until a certain threshold is reached, e.g. > 0.01 ŁTC.

I'm mining at around 100kH/s (867.9 block difficulty) and only recieving payments once every four/five blocks. This is a bit discouraging but in total I'm getting higher payouts than mining in normal pools.

By the way, the minimum recommended hashrate for p2pool-miners is 590 kHash/s.

Multiply by 65536 to convert to P2P difficulty to CGminer difficulty.

Answer 2

The p2pool payout method is based on PPLNS, so if your shares are not in the window of the blocks found, you will not get any payments.

I do not know if there is any other problem that could prevent you from receiving payment.

By the way, in centralized pools it is also true that you only get payment when a block is found, unless they are using PPS.