Quote from: Pizzi_h on November 29, 2018, 08:09:16 PM

Thoughts.

z9 mini
I have my miners Hosted outside, OR direct outside air, we have been having around -15c and the miner worked great got it up to stable at 681mhz since release.
2 fans front 1800rpm rear 1640 rpm Chips temp around 28-30c hash Avg 14.9ksols

Today the weather Drastically changed to +2c and i got all 3 boards xxxx

seems that it was the bm1740_verify_nonce_integrality CRC error. Reebooted but only took like 7min then got the same error again.
But after that ive only been able to maintain 656mhz.

soon as i go above that i loose one board.

CAN it be possible that the colder the chips can be maintained the higher mhz we can maintain? I never tried above 681mhz

This is a very good question. First on the CRC error -- that is going to happen some and is only a problem if it is constant. It happens on even the stock firmwares depending on machines, temps, frequencies, and phase of the moon.

Temperatures will play into how far you can push these, but there is not a clear formula for that. What's really interesting is I have a customer with a large install (1000+ machines) who has observed that there is a point where the machines get too cold and slow down! I'm unsure of the exact details on the temperatures, just the observation that was shared with me.

So yes, temperature has a play both when going up and when going down.

The summers here are very hot -- my miners I had to constantly tune even through the day to get maximum out of them; they always ran best at night.

I hope this helps some.

Jason