Do you mine bitcoins with ASICS ?
Yes, but not significantly at the moment. I am currently mining more scrypt based coins due to my setup (more GPUs) and the profitability in some coins compared to BTC. I plan on investing in a very nice btc rig soon though, as that seems the most profitable over time if one has money to spend on the hardware.
Interesting, the impression that I tend to get from this forum is that investing in BTC mining rigs is rather late and counter-intuitive (as the difficulty is already quite high)...so the return from these rigs is unlikely to recover full cost. Is that not true or is that just a way to tell people not to mine so that you get more chance to mine a full block yourself?
I may be wrong about this, but I read somewhere that the more people mine BTC, the difficulties also increase.
It is not a good idea to buy into a BTC rig unless one has the opportunity and the money to pre-order and buy a high-end miner. For example, if one bought a USB eruptor block when they were first (?) available for 1.05BTC, the probability of the eruptor paying itself off and making a profit was very low; on the other hand, if one pre-ordered a 500 GH/s mini-rig from Butterfly Labs when they were 25k USD (if I remember correctly) and received it a few months ago, the potential for great profit is there. For example, it has potential to produce ~3.824 BTC per day, calculated with price/difficulty as of now. If calculated for the factors a few months ago, the profits were even more substantial.
Regarding solo BTC mining... that would not be advisable to attempt unless one has over 1 TH/s (at least, much more in near future), due to the extremely rare chance of solving a BTC block solo with the current difficulty and amount of competition around the world to mine BTC.
For difficulty increases, from what I could tell from the white paper about BTC, by Satoshi Nakomoto (
http://bitcoin.org/bitcoin.pdf), it is determinate on the hash-rate of the coin pool (BTC in this case). As the hash-rate increases and the blocks are solved at a faster rate, the difficulty is automatically adjusted (every 2 weeks for BTC). The algorithm checks to see the average time it takes to complete a block, "the proof-of-work difficulty is determined by a moving average targeting an average number of blocks per hour. If they're generated too fast, the difficulty increases" (Nakomoto, p.3). Therefore, the algorithm will adjust the difficulty either up or down, depending on the rate blocks are solved. It does not always have to increase; an example of decrease difficulty in the BTC algorithm can be seen from December 2012 to about February 2013 (might be a bit off on dates).
In my opinion, it is usually not worth buying any mining equipment that is already mainstream, as it probably will not profit much, if at all (hence bulk sells). If the mining equipment is, on the other-hand, exponentially faster and more efficient, and the supply of the units is also low, there is a great opportunity for profits if one jumps at the right time and is prepared throughout. Just my opinion though, so take it how ya like; I can assure you that I am not trying to scare off others from mining BTC or any other coin. I was simply explaining my means and modes of production/relations with the digital currencies and the way I go about acquiring them.
Of course, this is just my method, opinion, and understanding of crypto-currencies; it probably is flawed or inaccurate in some areas, but it has proved to be an accurate and effective method to increase profits for me.
