I have not had enough sleep for days, but I don't think my math is that bad, 15.5 to 21.4 means we had a 5.9 hashrate increment, if not for the halving we would (in theory) have had double that which is 11.8, so 15.5T + 11.8T = 27.3T or 76%. I think your mistake was multiplying the total difficulty of 21.4 by 2 to make up for the halving, keep in mind that 15.5T of that is the old difficulty which has nothing to do with the theoretical new difficulty, do I make any sense?
The instant after the halving, it suddenly took 2X the work to mine the same amount of BTC. So if the purpose of the comparison is in relation to profitability, then I think multiplying the post halving difficulty by 2, or dividing the pre-halving difficulty by 2, is correct.
But in terms of using diff to estimate hashrate, there is no correction. The block reward amount does not come into the equation for diff correction, so 21.4T before or after the halving still produces the same estimated network hashrate.
As far as the ability to produce insane amounts of miners quickly, I don't think it would be as hard as you think for them to ramp up. And with this extended time of high profitability, they have plenty of time to secure contracts with all those giant >100MW farms, and expand their manufacturing capacity if required. They can't deliver those 37k miners until October because they have to wait for the chips.
The flip side of this, maybe Bitmain decides not to expand production even though demand is sky high, and then sell fewer miners at a much higher price point. Just seems like in the past, they do the opposite, and sell a ton of gear at prices low enough to try to really hurt their competition.
We have reached a point of gear not getting more efficient.
S19pro has 1 speed setting uses 29 watts a th
S17pro has many settings and the vnish set to 39th gets 25 watts a th.
That is a road block to hashrate growth also missing chips will slow rate.
In order to increase hash rate you need more power infrastructure.
Mining won't build a new dam as it is costly.
Mining can be leveraged to grow solar arrays.
I am thinking the next stage will be more solar arrays which were funded by mining.
If so we can have strong growth since a mining farm can say we help the environment as we increase solar footprint and lower carbon footprint
This is going to happen slowly but surely maybe this bull run will be the one that sparks this type of investment off. If so then we can have large hashrate growth as it would be decreasing carbon fuel burning.
I am not a tree hugger anti coal/gas/oil. guy I look at this from a practical viewpoint. I have seen and help build profitable solar arrays. That would scale 10x even 100x the 125k-watt field we run.
If global warming is real then this is the way to go.
If global warming is fake and the sun is simply a bit hotter then this is the way to go.
Why is that?
Sun will cool and the cheap solar power will reduce and like short sighted morons we have been buying all the coal the gas and the oil.
So either way solar is smart and carbo is stupid as fuck.
We could continue mining coal and storing it just in case the suns drops it's output. And we could be building cleaner coal plants just in case we need to switch back to them.
Oil and gas can stay in the ground for now.
Of course this would piss off gas and oil guys but they had a good run.
Also they purchased tons of solar tech so I am only telling you what will happen in 20 or 30 years from now.
All this relates to mining diff since mining will not grow without power. (40,000x the power for a gpu to a s17pro) Those power savings will not happen again. Maybe just maybe 10 watts a th is the best we will ever see.
I am not an expert on solar panels but with some friends that we have researched on that, the problem is that you need power 24/365 per day and solar can not give it you. You need batteries to be able to store energy and have a much bigger solar panel installation to do so. That is why everyone goes near geothermal energy or hydroelectric because this can be constant supply.