In the last few years there have been a number of huge changes in the industry currently involved in the mining of bitcoins.
It would seem that at this point the constraint brought about by ROI could make any further investments in hardware unsustainable even after the FPGA (field-programmable gate array) and the GPU were quickly replaced by new ASIC (Application Specific Integrated Circuits) and the inevitable battle for supremacy between manufacturers began.
Technology is clearly the first of the major issues to hit the bitcoin miners out there with companies like GlobalFoundries and TSMC both already using the latest 20nm and 28nm processor chips, and although the initial batches of 14nm and 16nm FinFET ASICs are not due out until next year the limitations of technology are already starting to hit chipmakers slowing their ability to improve things any further.
Getting around the thermal barrier is the first issue that chipmakers face whereby the only way to improve performance is to build chips that have more transitors but the addition of these extra transistors causes more heat which becomes increasingly difficult to get rid of.
Moore’s law and a variety of technical limitations means that even though ASICs, which are an emerging IC design, have seen massive growth over recent years it will not be possible for them to continue growing at the speed they have been.
This limitation, however, is not limited to just ASICs as all the major players in the chipmaking industry like AMD, Intel and Nvidia to name but a few are having the same problems.
According to Moore’s Law every two years there is a doubling of transistor numbers on chips. This, however, does not mean that there is a linear increase in performance as designers of chips can get far more out of the same number of transistors on a chip just by optimising the microarchitecture.
It is because of this that the design of ASICs will soon slow down as the technology ages even though it is far cheaper to optimise and develop the technology.
The latest cooling methods and optimisation of performance-per-watt will be required as the size of practical designs are limited because ASICs are already using the very latest technology. This will lead to a reduction in how fast efficiency and performance rise due to the additional money that needs to be spent to do this.
Any kind of focused analysis of ASICs is unlikely because these type of chips are not sold in large enough quantities and as the exact technical specifications of these chips are not disclosed by the ASIC designers there is no real way of knowing exactly what is offered except for the basics like the chip package size and the number of cores the processors have.
The current trend of investing too much in the equipment itself is the biggest issue for bitcoin miners and is one that is unsustainable in the long run. There has been a rise in the hash rate from 1 Million GH/s to 200 Million GH/s in the last year and the difficulty has gone up from 65 million to 27, 428,620,902 during the same period.