Comparison of mining pools
Reward types & explanation:
- DGM - Double Geometric Method. A hybrid between PPLNS and Geometric reward types that enables to operator to absorb some of the variance risk. Operator receives portion of payout on short rounds and returns it on longer rounds to normalize payments. 
- Prop. - Proportional. When block is found, the reward is distributed among all workers proportionally to how much shares each of them has found.
- PPLNS - Pay Per Last N Shares. Similar to proportional, but instead of looking at the number of shares in the round, instead looks at the last N shares, regardless of round boundaries.
- PPS - Pay Per Share. Each submitted share is worth certain amount of BC. Since finding a block requires <current difficulty> shares on average, a PPS method with 0% fee would be 50 BTC divided by <current difficulty>. It is risky for pool operators, hence the fee is highest.
- SMPPS - Shared Maximum Pay Per Share. Like Pay Per Share, but never pays more than the pool earns. 
- ESMPPS - Equalized Shared Maximum Pay Per Share. Like SMPPS, but equalizes payments fairly among all those who are owed. 
- RSMPPS - Recent Shared Maximum Pay Per Share. Like SMPPS, but system aims to prioritize the most recent miners first. 
- CPPSRB - Capped Pay Per Share with Recent Backpay.
- Score - Score based system: a proportional reward, but weighed by time submitted. Each submitted share is worth more in the function of time t since start of current round. For each share score is updated by: score += exp(t/C). This makes later shares worth much more than earlier shares, thus the miner's score quickly diminishes when they stop mining on the pool. Rewards are calculated proportionally to scores (and not to shares). (at slush's pool C=300 seconds, and every hour scores are normalized)
|Name||Location||GH/s||Merged Mining||Reward Type||Transaction fees||Fee PPS||Fee Prop / Score||Protocol||Launched||Difficulty||Forum||Website|
|50BTC||Germany||2500||?||PPS||kept by pool||3%||getwork||2011-11-11||1||1||Link|
|Bitcash.cz||Czech Republic||6||?||Prop.||kept by pool||0%||getwork||2011-07-21||1||1|
|BitClockers||USA, EU||235||NMC||PPS||kept by pool||8%||getwork||2011-05-27||1||1||Link|
|Bitcoin Mining Pool||USA||58||?||Prop.||kept by pool||0%||getwork||Unknown||1||1||Link|
|Bitcoin Pooled Mining (Slush)||EU/London||1430||NMC||Score||kept by pool||2%||getwork||2010-11-27||1||1||Link|
|Bitcoins.lc||EU||70||?||Prop.||kept by pool||0%||getwork||2011-05-27||1||1||Link|
|Bitparking||San Diego||170||NMC, I0C, IXC, Devcoin||PPS||kept by pool||2.5%||getwork||2012-01-08||1||1||Link|
|BTC Canada||Canada||110||?||PPLNS||kept by pool||1.5%||getwork||2012-08-08||1||1||Link|
|BTC Guild||USA, EU||2000||NMC||PPS||kept by pool||5%||getwork||2011-05-09||1||1||Link|
|BTCMine||UK||50||?||Score||kept by pool||2%||getwork||2011-03-11||1||1||Link|
|btcmp.com||Germany||160||?||PPS||kept by pool||4%||0%||getwork||2011-06-28||1||Link|
|Coinotron||Poland||7||?||DGM||kept by pool||0%||getwork||2011-07-06||1||1||Link|
|DeepBit||Germany||3350||No||PPS / Prop.||kept by pool||10%||3%||getwork||2011-02-26||1||1||Link|
|Eclipse Mining Consortium||USA / Europe / AU / Asia||1400||NMC||DGM / PPS||kept by pool||5%||0%||getwork||2011-06-14||1||1||Link|
|Eligius||Germany||400||NMC||SMPPS||kept by pool||0%||getwork, getmemorypool||2011-04-27||1||1||Link|
|Horrible Horrendous Terrible Tremendous||?||6||No||PPS||kept by pool||2%||getwork||2012-08-29||Changeable||1||Link|
|Mining Team Reddit (MtRed)||USA, EU||629||NMC||PPS||shared||0%||getwork||2011-05-25||1||1 2||Link|
|Ozco.in||USA/EU/AUS||800||NMC on DGM||DGM / PPS||shared on DGM||5%||3%DGM||getwork||2011-06-07||1||1||Link|
|pool.itzod.ru||Russia||200||Converted to BC||RSMPPS||shared||0%||getwork||2011-08-01||1||1 2||Link|
|Triplemining||Europe||90||On hold||PPLNS||kept by pool||0% ||getwork, getmemorypool||2011-06-28||1||1||Link|
|pool.mkalinin.ru||Russia||40||No||PPLNS||kept by pool||0%||getwork||2011-07-20||1||1||Link|
|alvarez.sfek.kz||Kazakhstan||3||No||PPLNS||kept by pool||0%||getwork||2012-04-19||1||1||Link|
- Note that pool hashrate is largely irrelevant but can be seen as a popularity measurement. Note however that it is a theoretical security issue if one pool gains above 50% of the total computational power of the network, thus consider joining a pool based on other metrics.
- Merged mining allows miners to mine on multiple block chains at the same time with the same hashing.
- The share difficulty the pool uses
- Pool also rewards stale shares
- Donations are possible
- Miner-local getwork proxy available.
- P2Pool supports merged mining but payouts in the merged chain are not pooled.
- People are donating to P2Pool miners to encourage people to use it. The P2Pool author also accepts optional donations.
- Triplemining keeps 1% to redistribute using a weekly jackpot and affiliations