Quote from: RichBC on November 29, 2015, 07:55:45 AM

Quote from: thebonenz on November 29, 2015, 06:18:43 AM

On Fri, Nov 27, 2015 at 11:57 PM, Sales Account <sales@blockc.co> wrote:
The smart speed is very important. The reason the fan control works the way it does is because the chip needs to run at 75C for optimal efficiency. When it gets too cold you get a high error rate. If you want to verify just set your fan to min 80% and your hash rate will drop to about 3.0T

Just trying to wrap my brain round this?.... A few thoughts.

So 75C chip temperature (Junction temperature?) is not that high and as has been said should not be confused with a temperature measured on the case of the chip or on the circuit board (as in an Antminer). However I would regard ambient as being yet another temperature to get confused with?

So does this imply that the ASIC's have a built in temperature sensor? If so then yes you would expect to run at a higher temperature than if there is a separate sensor on the circuit board.

However what I do not understand is the concept that "the chip needs to run at 75C for optimal efficiency" I could understand if this meant not higher than 75C but why would it matter if the temperature was lower than this? I have always understood when it comes to chips that colder is better?

So putting all of that to one side for the moment we are next told "When it gets too cold you get a high error rate. If you want to verify just set your fan to min 80% and your hash rate will drop to about 3.0T" Now that would first imply that during warm up there is a high error rate and that the system would somehow have to allow for this?

So coming now to turning the fan to 80% and the hash rate dropping. Question for me is does the hash rate drop because the firmware just turns the frequency down when you turn the fan up or does the HW error rate actually go up and then the frequency is turned down to reduce the HW error rate?

Again I am finding this confusing. Surely if the chip gets a bit cold and the frequency is then turned down the chip will then run even colder because of the reduced frequency and is just going to keep going down and down?

All very strange and confusing to me, hopefully the full and true story will emerge at some point?

Rich

Most miners can run hotter then advertised. It was not Avalon but another company I know of that gave a lower number to be safe on running temperature, but for big data centers it ran much hotter. I will not suggest others do this as I don't want to break your warranty.

As far as asic's having a temp sensor on chip... I don't think that is likely. From my readings and comparisons it seems temp sensor is close to exhaust side as temp out of exhaust and temp reading on GUI seem pretty close. But this is speculation

I think we still have a decent amount to learn as far as "smart speed". It seems to do great as far as overclock, but we need to understand it better to get that underclock (which I am still hoping for). The efficiency is still good for current gen as it is, so we have time to learn more.

Some have mentioned speed and fan percentage are directly linked with speed. I will test in coming day's and see what speed change on fan minimum does. Currently I have pretty cold air as ambient as I'm enjoying my window open, and the miner is still mining fine at 20 percent. I will specifically try 20 percent see results and then 80 percent and see results, most likely a 30 min or hour test on each.

I've ran over 5 day's at this point and no issues as far as rejects or other possible bad things with default settings. And my temp in room with ambient outdoors has varied greatly. So it seems to be able to handle a variety of ambient temps and still mine well.