sgminer/doc/FAQ.md

FAQ

Q: Why don't you provide binaries? A: Binaries are a hassle to maintain. On Linux, they should be provided by your distribution's package manager anyway. Runnning an unoptimised binary gives a minor performance penalty. Running binaries from untrusted providers is a security risk. There has not been sufficient community interest to provide distributed determininstic builds.

Q: It would be nice to have step-by-step installation instructions for Linux. A: These instructions cannot be specific enough, since it depends a lot on the GNU/Linux distribution you're using. It should be handled by the package manager anyway. Otherwise, such instructions will constantly be out-of-date. AMD does not allow redistribution of their SDKs' source code, so providing packages can be difficult for some GNU/Linux distributions.

Q: Why is the network difficulty wrong? A: It is not wrong. Sharediff of 1 (historically) corresponds to a network difficulty of 1/65536. Throughout the inteface, share difficulty is displayed as whole numbers, not fractionals. Pools use the same convention (with the notable exception of P2Pool). Until pools start using true network difficulty to display share difficulty, there is no reason to display difficulty differently. This is a vicious cycle and a remnant of Bitcoin mining on GPUs.

Q: Can you modify the display to include more of one thing in the output and less of another, or can you change the quiet mode or can you add yet another output mode? A: Everyone will always have their own view of what's important to monitor. The shipped NCurses TUI is intentionally ascetic, and is only provided as a fallback. It is recomended to use an API client if you want to customise the display.

Q: Can I mine on servers from different networks (eg litecoin and dogecoin) at the same time? A: No. sgminer keeps a database of the block it's working on to ensure it does not work on stale blocks, and having different blocks from two networks would make it invalidate the work from each other.

Q: Can I configure sgminer to mine with different login credentials or pools for each separate device? A: No. Run separate instances with -d.

Q: Can I put multiple pools in the config file? A: Yes, check the example.conf file. Alternatively, set up everything either on the command line or via the menu after startup and choose Settings -> Write config file.

Q: The build fails with gcc is unable to build a binary. A: Remove the "-march=native" component of your CFLAGS as your version of gcc does not support it.

Q: Can you implement feature X? A: I can, but time is limited, and people who donate are more likely to get their feature requests implemented.

Q: Work keeps going to my backup pool even though my primary pool hasn't failed? A: sgminer checks for conditions where the primary pool is lagging and will pass some work to the backup servers under those conditions. The reason for doing this is to try its absolute best to keep the GPUs working on something useful and not risk idle periods. You can disable this behaviour with the option --failover-only.

Q: Is this a virus? A: sgminer is being packaged with other trojan scripts and some antivirus software is falsely accusing sgminer.exe as being the actual virus, rather than whatever it is being packaged with. If you had built sgminer yourself, then you do not have a virus on your computer. Complain to your antivirus software company..

Q: GUI version? A: No. The API makes it possible for someone else to write one though.

Q: What are the best parameters to pass for pool / hardware / device? A: See doc/MINING.md in your source distribution directory, or [doc/MINING.md](https://github.com/veox/sgminer/blob/master/doc/MINING.md] for an online version. Note that the latter is for the latest development version, and arguments listed there are not necessarily available in your local version.

Q: Is CPU mining supported? A: No. Consider using cpuminer.

Q: I'm having an issue. What debugging information should I provide in the bug report? A: See doc/BUGS.md in your source distribution directory, or doc/BUGS.md for an online version.

Q: Is it better to mine on Linux or Windows? A: It comes down to choice of operating system for their various features. Linux offers specialised mining distributions, much better long term stability, remote monitoring and security, while Windows offers overclocking tools that can achieve much more than sgminer can do on Linux. YMMV.

Q: Can I mine with sgminer on a Mac? A: sgminer will compile on OSX, but the performance of GPU mining is compromised due to the OpenCL implementation on OSX, there is no temperature or fanspeed monitoring, and the cooling design will usually not cope with constant usage leading to a high risk of thermal damage. It is highly recommended not to mine on a Mac.

Q: I switch users on Windows and my mining stops working? A: That's correct, it does. It's a permissions issue that there is no known fix for due to monitoring of GPU fanspeeds and temperatures. If you disable the monitoring with --no-adl it should switch okay.

Q: My network gets slower and slower and then dies for a minute? A: Try the --net-delay option.

Q: How do I tune for P2Pool? A: P2Pool has very rapid expiration of work and new blocks, it is suggested you decrease intensity, decrease scantime and expiry, and/or decrease GPU threads to 1 with -g 1. It is also recommended to use --failover-only since the work is effectively a separate blockchain.

Q: Are OpenCL kernels from other mining software usable in sgminer? A: Most often no.

Q: How do I add my own kernel? A: See doc/KERNEL.md in your source distribution directory, or doc/KERNEL.md for an online version.

Q: I run PHP on Windows to access the API with the example miner.php. Why does it fail when PHP is installed properly but I only get errors about Sockets not working in the logs? A: See this.

Q: Will sgminer support FPGAs or ASICs? A: No. sgminer will only support GPUs. It is bad software design practice to try and support every gadget out there. Developers for dedicated hardware products are better off creating standalone software.

Q: What is stratum and how do I use it? A: Stratum is a protocol designed for pooled mining in such a way as to minimise the amount of network communications, yet scale to hardware of any speed. If a pool has stratum support (and most public ones do), sgminer will automatically detect it and switch to the support as advertised if it can. If you input the stratum port directly into your configuration, or use the special prefix stratum+tcp:// instead of http://, sgminer will ONLY try to use stratum protocol mining. The advantages of stratum to the miner are no delays in getting more work for the miner, less rejects across block changes, and far less network communications for the same amount of mining hashrate. If you do not wish sgminer to automatically switch to stratum protocol even if it is detected, add the --fix-protocol option.

Q: Why don't the statistics add up: Accepted, Rejected, Stale, Hardware Errors, Diff1 Work, etc. when mining greater than 1 difficulty shares? A: As an example, if you look at 'Difficulty Accepted' in the RPC API, the number of difficulty shares accepted does not usually exactly equal the amount of work done to find them. If you are mining at 8 difficulty, then you would expect on average to find one 8 difficulty share, per 8 single difficulty shares found. However, the number is actually random and converges over time, it is an average, not an exact value, thus you may find more or less than the expected average.

Q: Why do the scrypt diffs not match with the current difficulty target? A: The current scrypt block difficulty is expressed in terms of how many multiples of the BTC difficulty it currently is (eg 28) whereas the shares of "difficulty 1" are actually 65536 times smaller than the BTC ones. The diff expressed by sgminer is as multiples of difficulty 1 shares.

Q: Can I make a donation? A: Yes, see AUTHORS.md for authors' donation addresses.

Q: What is Work Utility (WU)? A: Work utility is the product of hashrate * luck and only stabilises over a very long period of time. Luck includes hardware error rate, share reject rate and other parameters. Therefore, it is often a better indicator of hardware or software misconfiguration.