Frequently Asked Questions

Difficulty Hard Fork

At block 135,000 a scheduled hardfork happened. Due to a bug in the new difficulty algorithm, the network difficulty first dropped to a very low number, and is now targeting a block time of approximately 30 minutes (instead of the correct 10 minutes). This bug is going to be fixed by a new hardfork which has been scheduled for block 139,000. Further information on the topic can be found here.
The only thing that you may need to do is to upgrade your Sia wallet software to at least version 1.3.1.
Mining software (such as Marlin and Claymore) does not need to be updated.
The hard fork at block 139,000 fixes the difficulty retargetting algorithm. It does not change any other aspect of Sia.

Reward System

Despite the similar names, PPS (Pay Per Share) and PPLNS (Pay Per Last N Shares) are two very different reward systems.
  • PPLNS is a modification of the proportional system. The proportional system is perhaps the most natural way to distribute rewards: whenever the pool finds a block, it distributes its value (minus a fee) to miners proportionally to how many shares they have submitted since the previous block. This naive approach is unfortunately easily exploitable by using a technique called pool hopping. PPLNS corrects this issue by considering only the last N shares submitted right before a block was found, and disregarding the rest. If the value of N is chosen appropriately, the system becomes resistant to hopping, but with one side effect: in order to receive fair retribution, in a PPLNS system miners must maintain a relatively constant hashrate at all times. Being a proportional system, PPLNS only rewards miners when a block is found and confirmed by the network, and since finding a block can take considerable time, rewards have a high variance. Additionally, from time to time the pool may find a block that never confirms because another block was found and confirmed before it. Such blocks, called orphans, have no value, and result in missed rewards for miners.
  • PPS rewards miners with a certain amount (the PPS rate) for every valid share submitted. This amount is determined based on the expected number of shares needed to find a block, and on the reward that finding a block would yield. Note that we say “expected” because mining is a random process, so we can know how many shares will be needed on average in the long run, but not how many will be effectively needed. Since shares are much easier to find than blocks, a miner typically finds several every minute, which drastically reduces the variance of rewards. It is therefore possible for a miner to reliably estimate his earnings, as they do not depend on the luck of the pool. Because miners get paid per share and can tally how many shares they submit, they can easily verify that the promised reward is given, making it impossible for the pool operator to cheat. For the same reason, PPS is completely immune to pool hopping. All in all, PPS arguably offers the fairest payouts for all miners, regardless of hashrate or frequency. The one downside to PPS is for the pool operator, who has to take on the risk of bad luck in finding blocks. To compensate for this risk, PPS pools traditionally charge a higher fee.
Everything else being equal (fee, difficulty, and block reward), in the long run both systems are expected to find the same amount of blocks, but since PPLNS cannot pay for orphaned blocks, PPS miners are expected to receive slightly higher payouts. There are several places on the internet where it is stated that PPLNS yields higher rewards than PPS. The only reason for this is that for a long time PPS pools have had much higher fees than their PPLNS counterparts. For instance DeepBit, which was once the biggest Bitcoin pool, used to charge 3% for PPLNS, but 10% for PPS. SiaMining, on the other hand, has a low 3% PPS fee.

To find out more about reward systems, we suggest reading the excellent paper by Meni Rosenfeld, available here. A summary of his analysis can be found here.
SiaMining comes with a 3% fee, which is very low for a PPS system. It pays for the following:
  • Hardware and staff costs necessary to run SiaMining.
  • Covers the cost of the pool taking the risk of orphans and block solving variance.
  • Covers the transaction fees for miner payouts.
No. Block rewards are used to pay the work done by all miners, so an extra reward to block finders would mean diminished returns for all other miners. We believe rewarding all miners equally is more fair and transparent, and ensures a fair incentive to all miners, regardless of their hashing power.


Depending on your miner, make sure it’s compatible with SiaMining. See the list of miners available here. Make sure that you are using the correct port and that your address is correct (you’ll get an authentication error if it’s not).
This could be due to a myriad of issues: high intensity, overclocking, hardware issues, network issues. Ensure your network is stable and you are using the SiaMining server closest to you. If you are overclocking try with stock clocks first, increasing clocks only after stability has been reached. Not all GPUs are built from the same silicon, and universal overclocks aren’t ensured.
There is! MineMonitor for Android, and Blockwatch and MyMiner for iOS.

Disclaimer: these apps were written by independent developers, not affiliated with SiaMining.


Our payout schedule is optimized for both small and large hashing operations. Payouts are performed daily with a minimum threshold of 500 SC, or up to every 6 hours when over 1000 SC.
If you stopped mining and your balance is over 100 SC, you can request a final payout by sending us an email at
First of all, check the link to the explorer from the Recent Payouts section on your address page. If a transaction is displayed, it means that it has been successfully included in the blockchain. If the transaction is not showing in your wallet software, make sure that your wallet is synced with the blockchain. You may need to rescan. If you are using an addresses from an exchange, and you don’t see the transaction within a reasonable time, you will need to open a support ticket with the exchange.
If you get a “Hash not found in Database” error with the explorer, it may be an occurrence of a long-standing bug with the explorer. Wait a while and try again.

Disclaimer: we do not operate the explorer, it is run by the Sia developers.

Last but not least, the obvious: make sure you are mining to your own address! There have been folks mining to the default address in the sample batch files. You’ll need to change it!
If you would like to change your payout address, mine until your current address has over 500 SC, then switch your miners to your new address. if you have lost access to your original address, we are unable to move the coins to a new address, as there is currently no way to prove ownership of an address (unlike Bitcoin, Sia hasn’t implemented message signing and verification yet).