The computational power of BCD

when building bitcoin, Nakamoto wants bitcoin to be a decentralized currency, not only for use and trading, but also for mining. But it backfired. With the increasing value of cryptocurrency such as bitcoin, mining has become an instry. The competition is more and more fierce, and the pursuit of mining computing power is higher and higher. Therefore, from ordinary computer mining, ASIC mining machine and GPU mining machine have evolved

the algorithm of ASIC mining machine is almost sha256, while the algorithm of GPU mining is different. For example, the algorithm of BTG is equihash, and the algorithm of BCD is optimized x13. Although it is not absolute, it can be simply considered that the currency of sha256 algorithm is generally mined by ASIC mining machine. Other algorithms are basically using GPU miner. There are also exceptions. Scrypt's Leyte coin used to be mined by GPU miner, but later scrypt's algorithm was also conquered by ASIC chips, such as ant miner L3 +, which is the ASIC miner used to dig Leyte coin

ASIC miner refers to the miner that uses ASIC chip as the core of computing power. ASIC is the abbreviation of application specific integrated circuit, which is a kind of electronic circuit (chip) specially designed for a specific purpose. Some mining machinery factories have designed ASIC chips specially for computing the sha256 algorithm of bitcoin, and the mining machinery using them is ASIC mining machinery. Because ASIC chip is only built for specific computing, its efficiency can be much higher than that of CPU. For example, the current mainstream ant miner S9 is ASIC miner, which uses 189 ASIC chips, the computing power reaches 13.5th/s, and the power consumption is only 1350W. As a comparison, the computing power of gtx1080ti, the flagship computer graphics card, will not exceed 60mh / s even if it is optimized well. The difference is tens of thousands of times

the purpose of GPU miner is to make money, so we should pursue the power consumption ratio and maximum profit, so we should pay attention to the cost performance. Generally, the medium and high-end positioning graphics cards, such as AMD rx560 and rx570, have high power consumption ratio, which is a good choice for GPU miner. While flagship cards such as gtx1080ti and AMD vega64 have the strongest single card performance, they are not cost-effective in terms of price and power consumption

in addition, the ASIC miner also has some exotic procts, such as the USB miner of burning cat, which is slightly larger than the U disk, and the power consumption is only 2.25w, which is the smallest bitcoin miner at present

the above quoted digcoin.com - "Introction to mining machinery classification" has many professional terms. I hope it can help you, thank you

When two BCD codes are added, if the sum is equal to or less than 1001 (i.e. decimal number 9), no correction is needed

if the sum is between 1010 and 1111 (i.e. hexadecimal number 0ah ~ 0Fh), it needs to be corrected by adding 6

if carry occurs in the standard when adding, 6 should be added to correct

the reason for this is that the machine adds by binary, so when adding 4-bit binary numbers, the operation is carried out according to the principle of "every 16 into one". In fact, it is the addition of 2 decimal numbers, which should be added according to the principle of "every decimal one"

16 and 10 is 6, so when the sum exceeds 9 or has carry, 6 should be added to correct. Here is an example

[example 1.3] examples of BCD code operation value need to be modified

calculation 5 + 8:

solution: input 5 and 8 as 8421 BCD, then the calculation is as follows:

0 101

+ 1 000

1 101, the result is greater than 9

+ 0 110 plus 6 correction

1 001, that is, 13 BCD code

result is 0011, that is, decimal number 3, and it also proces carry. 5+8=13

{rrrrrrr}

classification of BCD Codes:

BCD codes can be divided into weighted codes and non weighted Codes:

weighted BCD codes have 8421 codes, 2421 codes and 5421 codes, among which 8421 codes are the most commonly used; No right BCD codes have 3 codes, 3 cyclic codes and so on

1, 8421:

8421 BCD code is the most basic and most commonly used BCD code, it is similar to four bit natural binary code, the weight of each bit is 8, 4, 2, 1, so it is called weighted BCD code

and 4-bit natural binary code is that it only selects the first 10 groups of codes in 4-bit binary code, that is, 0000 ~ 1001 are used to represent its corresponding decimal number, and the remaining 6 groups of codes are not used

2, 5421 and 2421:

5421 BCD codes and 2421 BCD codes are weighted BCD codes, and their weights from high to low are 5, 4, 2, 1 and 2, 4, 2, 1 respectively

in these two weighted BCD codes, some decimal codes have two weighting methods

Network BCD code

The full name of BCD is binary code decimal, which means binary in Chinese