public-pool.io, hashrate is not stable

[PSLLSP]

NerdMiner connected to pool public-pool.io is not hashing at the highest possible speed, hashrate is not stable, it oscillates between zero and maximum. I was observing this issue for some time but I assume it is because miner is overheating or it has problem to connect to WiFi (too many WiFi devices in my place...).

When the same NerdMiner is connected to pool solo.ckpool.org, it hashes at stable hashrate, about 78 kHps (firmware v1.6.3).

I am not sure what is source of this issue, it could be firmware or pool. I bet on the pool, because I observed similar "unstable" behavior when I tried to mine other coins (BTH, XEC, CHTA, etc) in pools those are not optimized for NerdMiner low hashrate...

I test with NerdMiner v1.6.3 running on LILYGO T-DISPLAY-S3 (ESP32-S3). I noticed this issue in the past with firmware v1.6.1 running on T-DONGLE-S3 but I was not reported it, I assumed that dongle is just overheating...

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When only one or two devices are connected to the pool, hashrate is stable. When I run more devices (like 10), I see stability issues. I assume it is related to WiFi, that device finishes work but it cannot get new task in time. Maybe that pool sends tasks in some synchronized way, so several devices try to connect to the pool in the same time and WiFi packets collide and some devices doesn't get new task in time and hashrate goes down...

It is possible that public-pool.io sends new tasks more frequently than solo.ckpool.org, so probability of WiFi collision is higher when miners are connected to public-pool.io.

[BitMaker-hub]

The hashrate dump from max to 0 is regarding USB port. There is an extrange behaivour when you connect it to any PC that nerdMiner thinks has to send the log data and starts filling the UART memory. When this happens and the UART port is not oppened from the PC side this data never goes out and induces this kind of error.

That's why we don't recommend pluggin the NerdMiner on a PC, just plug it in your USB power adapter

[IT-Cru]

I have similar unstable rate at public-pool.io after upgrade NerdMiner with v1.6.3 release.

My 4 NerdMiners are connected via a QuatroBOARD 4 Nerdminers at a USB power connector which previously run stable at around 56kh/s on v1.6.2 release. Today I've upgrade one of them to v1.6.3 release for testing which show now this unstable hash rate. It is going up and down from 0 to 78kh/s.

When during flash of firmware (done via https://flasher.bitronics.store/) nothing in config has changed I would exclude issue from any WiFi connection, because other 3 ones are running stable with old 56kh/s hash rate with same WiFi connection on v1.6.2 release.

Let us now, if we could provide somehow any debug information for deeper investigation :)

[julio-matarranz]

@IT-Cru are you sure you gave them enough power ? Maybe your board in 1.6.3 is possibly consuming more power ? My hashrate seem to be more stable after changing how I power my boards.

[marssystems]

Power your NerdMiner with a 5V 2A mobile phone charger - it will run stable.

[PSLLSP]

Power your NerdMiner with a 5V 2A mobile phone charger - it will run stable.

No, that is not source of the issue. 5V/2A, that is only 10W. I power 3 NerdMiners with USB hub that is powered with 15V/3A power supply, that is 45W (15W for each NerdMiner) and I still see those hashrate oscillations... That USB hub can power four 2PAC miners from GekkoScience and those run really hot, they require active cooling. NerdMiners doesn't require active cooling, I guess that they consume only about 1W each... Power supply 5V/2A could power about 10 NerdMiners... 5V/2A can power RPI computer, that one can hash several times faster than those 10 NerdMiners... 1 thread at RPI4 can hash at speed about 900 kHps, when 4 threads are running, it is about 3.6 MHps, that is like 45 NerdMiners hashing at 80 kHps...

The best explanation of this mystery is that NerdMiner tries to send log data to serial port but PC is not listening so log data are stuck in the output buffer; read this comment

The key point is that any USB charger has enough power to power NerdMiner and those will run at stable hashrate as these charges do not activate serial port on NerdMiner... Maybe that this is not the case for NerdMiner based on ESP32-WROOM, those use external UART chip; those has no display so hashrate is not visible and when serial console is connected, than the issue is not there... ;-)

I see the hashrate oscillations because I power my NerdMiners from USB ports in PC (or USB hub connected to PC).

[IT-Cru]

Short update from my side.

I've tested to power up upgrade one without QuatroBOARD with same USB-C cable / power connection and then it runs stable at 78kh/s.

After this I reordered placements in positions on the board and when I put the already upgrade NerdMiner node at first slot it also runs stable at 78kh/s together with other non-upgraded ones.

My next step would be now to upgrade one more to see if it happens again.

[IT-Cru]

In my case issue seems to be resolved. I've updated now all of my 4 NerdMiners to v1.6.3 and they are running stable with same power connection like before at QuatroBOARD.

First one I've updated direkt on the board, maybe this was the issue for unstable hash rate.