Materials for calculating hashes for a beginner?

Question

Cryptocurrency

I am looking for a detailed article (no matter Russian or English) on the topic of mining in general, hashes, CPU efficiency, video cards. In particular, there are questions:
Now, for the most part, they mine on video cards; it's more efficient. Let's drop specifically mining, bitcoins and any cryptocurrencies, questions are purely about the technical side:
1) What happens directly during the calculation of hashes on the video card, what kind of operation is this, what is its input data and what is the result
2) What are the specifics of these calculations? Why is it more efficient to produce them on video cards than on a CPU?
3) However, there are several cryptocurrencies that are mined on the CPU. They have a different algorithm inside. How is it different. Who made it different and why?

Answer 1

1) Oddly enough - the hashing operation. This is a function. The input accepts an array of bytes of arbitrary length (+ the encoded length of the array) padded with zeros, if necessary, up to a multiple of the size. The output is an array of bytes of a fixed size.
From the point of view of mathematics, this is a surjective mapping of an infinite countable set into a finite one.
2) CPU will calculate one hash much faster than GPU. But modern desktop 4-core processors can only calculate 4 hashes at a time (by the number of cores). And there are thousands of computing units in video cards, and everyone can independently calculate the hash. Therefore, when millions of hashes need to be calculated, video cards win.
3) Only-CPU algorithms differ primarily in the required amount of memory. Each iteration requires its own piece of memory. If the hash for calculation requires 2 gigabytes of memory, then a video card with 4 gigabytes can only calculate 2 hashes at a time (or even one at all - do not forget about overhead). And a CPU with this amount of memory can count the same number of hashes. Only the CPU will do it much faster.
They did this primarily not against video cards, but against ASICs.