Looking for more information about reduced hashrate miners

[Steve Sokolowski]

Hi,

I'm performing an investigation into one customer who has encountered reduced hashrate from his L3+ miners. He said that, around June 21, his miners suddenly saw their hashrate decline by about 10%, and that the difference has persisted since then.

Has anyone else encountered this problem? If so, could you provide your username along with as much detail as possible about the issue?

Thanks,

-Steve

[jeffms2003]

I just started all mine on here a few days ago and I’d say my 2 hour average hash rate is about 10% below what is reported oin the firmware of the miners. I will have to test at other pools to determine if it is a pool issue. Is there a way to see a 24hr calculated avg hash rate on your site outside of the graphs?

[alim]

I have had similar experiences of late..

In particular it drops and never recovers after finding a block. I'm also seeing many more stale shares submitted.

You may notice me rebooting my miners. I thought solo mining would fix that, but that dropped that hashrate even further.

[Steve Sokolowski]

I just started all mine on here a few days ago and I’d say my 2 hour average hash rate is about 10% below what is reported oin the firmware of the miners. I will have to test at other pools to determine if it is a pool issue. Is there a way to see a 24hr calculated avg hash rate on your site outside of the graphs?

Are you saying that the stale shares make up for the 10% lower hashrate? I don't see a large number of stale shares, but it's possible that a few people have 10% stales.

[jeffms2003]

No, I rarely have stale share rejections (that was alim mentioning that). I did have an issue the other night where all my s9 machines had a work restart delay of "need more shares" for several minutes, but not sure if that is a separate issue. All I'm saying is that in my antminer firmware my average hash rate over 2-3 days is 10% higher than what my typical 2 hour average shown on prohashing.

About an hour ago I changed the miner configuration on all my miners to exclude the stratum argument before "prohashing.com:xxxx". Also on a couple of them I was testing the #xnsub command at the end and I removed that.

Right now the hash rates on the site are in line with what I would expect, but I will take a look at it again in a few hours and see if it stays consistent over several hours.

[jeffms2003]

I did test all my machines independently prior to having my mining room built out and didn't have that type of discrepancy over a 24hr period. It's possible over 2 hour periods, but I don't really have any 24 hour period to see here. I do check the 2 hour average often, though.

[jeffms2003]

Well after a few hours of running, we're back down to my averages of 10% below what I should be showing. For example my miners are running at 55 TH/s for SHA, but the 2 hour measurement on prohashing is 50.3, which is my 10% variance I've consistently been seeing. Similar % breaks on scrypt and equihash. I'll probably run for a week on prohashing and then test a BTC/BCH pool that mines whichever is higher profit, litecoinpool.org for scrypt, and a pool that just mines zcash and compare unless you guys figure out if there is an issue. It'll be interesting to see the results.

[alim]

Something is definitely different.

I decided to solo mine. Usually you get a small amount from the merged coin mining, but that is not happening this morning at least on least on the Scrypt machine.

FYI also mining on SHA - which says it found a block but I can't see it in the block list...

[alim]

I switched the coin and the merged mining is working.

Again the miner has said it has found a block, but is is not in the list, even as an orphan.

[Steve Sokolowski]

Well after a few hours of running, we're back down to my averages of 10% below what I should be showing. For example my miners are running at 55 TH/s for SHA, but the 2 hour measurement on prohashing is 50.3, which is my 10% variance I've consistently been seeing. Similar % breaks on scrypt and equihash. I'll probably run for a week on prohashing and then test a BTC/BCH pool that mines whichever is higher profit, litecoinpool.org for scrypt, and a pool that just mines zcash and compare unless you guys figure out if there is an issue. It'll be interesting to see the results.

It's possible that, because the hashrates are calculated over the last two hours, the displayed hashrates could be lower for one period of time, and then higher during other periods of time. The mining server doesn't have access to the actual hashrate of the miner; it can only extrapolate it from share data.

Have you ever seen a period when hashrate was higher than what the miner displayed?