First post. Long time lurker. I need help. I ended up with 10 gridseeds (5 chip) to get my feet wet with altcoins. I've read the quoted post and my numbers are still way off. Clevermining is reporting just under 600KH/s and cgminer is telling me I am hashing at over 4MH/s. Obviously I am doing something wrong...
Screenshot attached:
https://i.imgur.com/X8cbCnP.jpgI am making this post as a summary of issues with some ASIC miners having lower hashrate than expected to link it from the OP:
Short version
If you have ASIC miner and your 24-hour hashrate average reported by CleverMining is lower than expected, then you should try to setup a manual difficulty based on these rules:
- if your miner have 16 chips or more, multiply your miner MHs * 32 and round up to the next diff value. E.g. 3.5 MH/s miner with 16 chips: 3.5 * 32 = 112, round up to 128.
- if your miner have 32 chips or more, multiply your miner MHs * 16 and round up to the next diff value. E.g. 12 MH/s miner with 32 chips: 12 * 16 = 192, round up to 256.
- if your miner have 64 chips or more, multiply your miner MHs * 8 and round up to the next diff value. E.g. 28 MH/s miner with 128 chips: 28 * 8 = 224, round up to 256.
Remember that valid difficulty values are powers of two: 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536.
Please never use difficulty lower than your MHs * 8.
Longer explaination
There are some ASICs with faulty chips which tend to go dead/frozen if new work is sent very frequently (and CM switches coins more aggressively than other pools). Miner's controller probably restarts them if they don't send a share within reasonable time but that reasonable time is probably based on difficulty and expected time to find a share by the chip. The pool's vardiff adjusts difficulty so that your miner find a share very 10 seconds, but if you have dozens of chips inside one miner then it means each of your chip finds a share once per 5-15 minutes. If the miner restarts dead chips after 3x this time of not producing a share, then your chips can be frozen for half an hour before being restarted. If your miner has lot of frequently faulting chips then this will result in lower hashrate (because some of your chips are not working) and hashrate going up and down randomly. This doesn't happen on single-coin pools and doesn't happen on coin-switching pools which are switching coins slower than CM. This also doesn't happen on CM with miners which don't have faulty/freezing chips. Try setting manual difficulty according to rules above depending on number of chips and check if this will help. It helped most of people who had similar issue.
Also, when you test everything with these values, please try to use one step higher and see if it's still OK. So if you have 12 MH/s miner with 32 chips and you used 256 and it's OK, change it to 512 and see if it's still OK, because at 256 your miner will send one share per 1.4 second and this is too frequent (and 28 MH/s miner will send two shares per second). This should be used only as emergency if your miner has issues with higher difficulty - as an exception, not a rule.
Sending more frequent shares than one per 10 seconds makes sense only if your chips are falling dead and you need to make them find shares faster (in order to faster detect if they're dead and not sending shares as expected and to restart them). Hammering the pool with one share per second isn't healthy neither for the pool nor for you (using more bandwidth) and should be used only if necessary.
So, if you don't experience issues, just use VARDIFF. If you play with manual difficulty, always please check one step higher to see if it also works fine with your miner. All this manual difficulty should be needed only for miners with falling chips where the miner controller silently restarts them if they're dead - which is quite rare actually.