My only Spondoolies experience was with the SP20. As Phil said it was a very solid piece of gear. It was almost infinitely adjustable in terms of hash rate between it's limits. The 800GH figure was great, but 1000GH was equally solid and more efficient than anything higher. The fan speed (aka sound) also moderated quite well with lower speed (meaning quieter). My subsequent Avalon miners really didn't have that kind of adjustability, and the fan speed never got as quiet.  

It's not obvious that Bitcoin mining has matured enough that that the "data center rack miner"  concept is viable long term. The only thing that's making recent gear continue to be useful is constrained supply of new chips. Since an ASIC miner is strictly a machine for converting electricity to money (aka BTC), it doesn't quite fit the model of what a data center does. At a very gross level yes, but not at the rack level, and not the overall purpose. Maybe some day (IMHO).

I am quite certain that the vast majority of folks that are looking at BTC as an "investment" have little interest in a a moderately static price of $45K to $50K. I still read articles that are pushing BTC price of $100K by years end. They may well just out for the "pump and dump" but if BTC breaks to $65K or higher, difficulty will follow in the same direction until every single S9 is restarted.

I also think that there has been some hashrate in the USA that's been dormant because of hot summer weather in the country. As the weather cools some of that will get switched back on. I don't know how much that is in aggregate.

We are down to the end of the current epoch, and BTC price comes through in terms of excitement. A roughly 8.5% decline in price down to $47,539. I thought we had broken through the "resistance level of $50K", but was re-educated on the dynamics of BTC pricing and where it's headed. 

Wow, that was quick! BTC price has been right about $50K for a couple of days, but couldn't quite hang on. Now it has just blown through and hit $51,700. We'll see if that will hold. That will likely help to cement a +2% difficulty increase this week if it does.

We are now well past the halfway point in the current epoch:


This really looking good for small increase to possibly zero change. BTC price continues to flirt with $50K but can't every really get there for more than a few minutes. I personally don't think that whatever gear was pushing the hash rate when BTC price was $64K is actually gone. I might be in transit or powered down for reason phill suggests, or it's barely profitable at the current BTC price. I am also a firm believer that when BTC price gets high enough, there will lot's more hashrate following along in short order.

Unfortunately after the most recent difficulty increase, BTC price has fallen to less than $47K. A couple of days ago there was brief push to just above $50K that didn't hold. I have identified one item that seems to drive BTC price. I call it EMF (not Electro Magnetic Force) which stands for "Elon Musk Factor".   

Into the home stretch for this epoch:


Current BTC price: $46,329.

This increase is going to sting a bit.

At exactly the midpoint of the current epoch:


Another increase in difficulty is almost certain, probably in the range of 5.xx%.

BTC price currently is: $42943 (pretty good recovery).

Well past the 75% mark for this epoch.


With BTC price at roughly $40K, this will likely be a solid increase in difficulty. Looks to me like some portion of the missing hash from China has found a new home.

Is there a limit on how MUCH of that .05 EUR/Kwh is available at the location you chose? How about cooling at that location? How about noise produced by the miners at that location? Is there Internet access available? I would expect that with five S19 Pro you'll need wiring for at least 20 Kilowatts of electricity.

I ask these questions since I didn't see anything about the TYPE of business (Industrial, Office, Manufacturing, etc) that might have problems supporting a mining operation.

Could you elaborate on the feedback loop whereby a change in difficulty influences BTC price? I can easily understand and describe how BTC price influences difficulty over time, but the reverse is hard for me to visualize. I know you stated it was low, but I am just not seeing it.

I am really mot seeing the correlation between difficulty and BTC price that the above suggests. It seems to me that the roughly 45% decline in BTC price was well before (in time) the most recent large drop in difficulty. The big decrease in difficulty seems attributable to a bunch of mining hardware in China being switched off.

Why will that restart of mining hardware then spur an uplift in BTC price?

I will freely admit I have no idea what drives BTC price. Please just explain how difficulty changes influence BTC price, and in what directions.

Why the desire for a difficulty increase? Seems counter-intuitive to me (from a miner point of view).

As we slowly grind through the current epoch, we are nearly 75% done (1487 / 1934 expected). Per cryptothis, that's about 77% of the expected pace. Clearly a big chunk of hash rate is "missing" even from the end of the last epoch. Glad that @kano weighed in above with another little tidbit about Bitcoin difficulty calculation.

No real joy on the BTC price front: $32,945. Unless Mr. Fuzzy went big on his last BTC purchase he is probably "underwater" for his last pair of announced trades.   

I hope @Phil is OK since he hasn't hit this thread in a while.

While we are currently short of the mid-point for this (966 / 1152 expected), we are well over a day "behind where we should be. This pointing to another drop in difficulty> This doesn't appear to be just "variance" but a sustained reduction in hash rate. I've seen news about some China based farms looking for a new home. I've also seen Texas (her in the USA) suggesting that they "are open for business". That doesn't seem like a good idea since their electrical grid is under serious pressure due to the heat here across the USA.

No joy on BTC price at the moment: $32,468. I think this qualifies a "Bear" market for BTC given the decline from it's high, and the duration of that decline.

I would also suggest that the "heat wave" being experienced in parts of North America might well have dropped some hash rate. Here in MN my residential electricity provided has switched to it's higher summer rate. My single A841 inside my home basement is now off probably for the summer when I have AC on. It was "fine" during the winter months and a high (well above the current $37,697 price), but the current BTC price, my electric cost, and the heat is a sure sign that my A841 should now be resting.

The outlook so far is for a "warmer than usual" summer here in Minnesota. I expect that will be true for much of the USA.

P.S. We just finished block 2015 so the current epoch will conclude "soon".

We are now at block 849 in the current epoch. That's only slightly ahead of the expected number of 845. Since the last epoch ended on May 29th with a drop of -15.96% we have been pretty well on track. Right now it looks like the difficulty is pretty well matched with actual hashrate. This could be a near zero change on June 12th.

Unfortunately BTC price remains depressed at $37,133. 

We are now slowly moving to close out the current epoch. We now have about 120 more blocks to go, and are running at about 85% of the normal expected pace. crytothis predicts we will finish tomorrow (Saturday) early in the evening. We are well past 15 days into the epoch and running about 350 blocks "behind". The projection is for a decrease of roughly 15% in difficulty.

On the BTC price front, it's at $35,867. Looks to me like most of the air has been let out of the balloon and will take a while for BTC price to recover (or re-inflate). Don't know what will push BTC price one way or another, but has been in a trading range of $36K to $39K for the last 10 days.

P.S. Looks like @Fuzzy won't get his $30K speculative order filled soon. That's probably a good things.

At roughly the halfway point of this epoch (1005 blocks mined), we are currently 181 blocks "behind" where we are expected to be (based just on the number of days). While plenty of time for things to change, cryptothis is currently projecting a decrease 0f -13.xx% to end on May 29th.

Unfortunately BTC price is sill way down at $37,479.