Why diff has risen so much? Any new miner or just the coin become more and more popular
?
Its nice and easy to track as the block difficulty is directly related to the hashrate, here's the graph
http://monerochain.info/charts/hashrateThe rise from July 15th to 19th is likely linked to the pump up to nearly 0.006BTC/XMR around that time, the climb over the last two weeks has been less spectacular but consistent.
I havent discussed it much with other pool admins but the only miner improvements recently have been for Nvidia cards, I'm not sure they are significant enough to explain the rise unless they have made the XMR ROI better than other altcoins. In fact I'm not sure what the return is like compared to other coins/algos currently.
It seems that botnets still comprise around 25-50% of the hashrate (I'm not going to debate whether that is "a bad thing" right now), which makes a lot of infected PCs - I wonder if more AV suites and MS Defender will be adding miner sigs to their malware lists and starting to kill that off, but that's probably being too optimistic about the bot owners security practices...
Unfortunately despite the rise in hashrate it still seems to be concentrated on a few pools, which is certainly a bad thing. Seems all those big coloured text pool ads failed to achieve much other than get pool ads banned
I'd like to think the recent rise is down to lots of new Monero adopters but I suspect its a smaller number of miners discovering its a more reliable income than swapping altcoin/algo every couple of days.