A FPGA (user-programmable gate array) is a cryptocurrency mining equipment that is very similar to an ASIC except for one key feature.
- ASIC is a chip that is hard-coded to perform one type of computation (for example, for Equihash mining).
- An FPGA is a chip that can optionally be reprogrammed to perform any operations .
In the field of mining, you can reconfigure FPGA from Cryptonight mining to Lyra2z mining in seconds. With processors and video cards, this can also be done, but for certain reasons, FPGA runs much faster.
It is known that certain FPGA boards work 100 times better than graphics processors with the same power consumption. Depending on the algorithm, the FPGA may lag a little or not fall behind the ASICs altogether.
The principle of operation of FPGA chips
For mining on the FPGA, the bitstream is written – the chip's firmware, which indicates how the FPGA should solve the problem necessary for the mining of a particular coin. Programmed bitstream in Verilog or VHDL.
An FPGA chip is a semiconductor. Used in cases where the device is designed to perform logical operations, such as and, or, nand and others.
That is, it is a microcircuit with duplicate logical blocks connected in a circuit. They can be configured at their own discretion according to the tasks.
Equipment based on FPGA was originally designed for air cooling. With it, the working temperature of the chip reaches 100 degrees. When operating chips in such conditions, one of the leading manufacturers – the company Xilinx – gives a three-month warranty. But with immersion cooling, the chip temperature does not exceed 80 degrees.
Due to this, the entire board and all the chips that are on it work in ideal conditions for them. This significantly increases the lifetime of the chips and automatically increases the hashing rate.
Pros FPGA:
- one FPGA card is equal in performance to 20-40 video cards, when consumed, as in 1-2 video cards;
- FPGA flexibly moves from one algorithm to another, so no software forks can stop the work of a mining farm ;
- It requires several times lower infrastructure costs (electrical, cooling, etc.)
Cons FPGA:
- FPGAs are not available for mass mining, as there are fewer cards produced than the number of people willing to buy them;
- Card programming is a time-consuming process of creating a bitstream from scratch in non-popular Verilog or VHDL languages, which has led to high development costs;
- FPGA is much more expensive than GPU and ASIC, therefore it is suitable for large mining players rather than home farmers.
Evolution of mining equipment – from CPU, GPU, FPGA, ASIC
The history of bitcoin mining began with the use of CPU (processors) in 2009. In the summer of 2010, the rate of the first cryptocurrency rose to $ 0.08, then the mining began to generate revenue, which provoked increased competition among miners.
This led to the transition of mining to industrial rails – the use of GPU (video cards) . Video cards had a ten times faster hashing rate at a lower cost. The clear advantage of mining coins both on the CPU and on the GPU was the ability to switch from one to another, depending on the market situation.
In 2011, some enthusiasts began searching for less energy-intensive mining devices, and found FPGAs. Farms with FPGA cards were many times more productive and energy efficient, but expensive and difficult to program. In 2013, the first ASIC appeared – sharpened for the extraction of one coin, powerful and easy to use.
The mining economy has changed. The main factors of change include bear market cryptocurrency and the ever-increasing complexity of mining. Therefore, the hashing power and ease of use of the appeared ASIC determined their popularity.
The increase in the number of ASIC led to another problem – the centralization or the so-called risk of “attack 51%” of many large coins, which forces developers to change the hashing algorithms.
The big disadvantage of ASIC for miners is that in case of a change in the hashing algorithm, mining on them will be impossible, since the computational algorithm is sewn into the “stone” and cannot be changed. It remains only to buy ASIC and hope that the investment will pay off before the mining algorithm of the coin changes or the complexity of mining this coin does not rise to the skies.
GPU mining is still a working option, but the high power consumption of video cards makes mining a pointless exercise in many regions where the cost of 1 kW / h of electricity is above 7-12 cents in the current market situation. Of course, mining equipment manufacturers are thinking about whether there is an alternative to ASIC and GPU? Solution found – back to the FPGA-chips.
Comparison of FPGA miners with ASIC and GPU
FPGA (English Field Programmable Gate Array) or user-programmable gate array is one of the varieties of FPGAs (programmable logic integrated systems) – an integrated circuit that can be reconfigured for any complex computational problems.
The first FPGAs for commercial use were developed in 1985, they were used in scientific calculations, military electronics, telecommunications, video stream processing, medicine, industry, etc. In these areas, FPGAs are still used today. In the field of mining cryptocurrency FPGA can be configured to mine different coins within a second.
Unlike CPU and GPU, FPGA-card can be reprogrammed for the task solved on it. One of the most important features of FPGA for mining is reduced power consumption per unit of computing power.
If FPGAs are so versatile, why have they not yet forced ASIC out of the market? This equipment is not widely used for several reasons.
Reason one: FPGA is not easy to configure due to the flexibility and architecture of the card. They can be programmed for anything, but this requires the knowledge of unpopular low-level languages – Verilog or VHDL. And if the video card can be configured using the BIOS and miner, then the FPGA card must be programmed from scratch, and this takes time.
From this reason comes the second – the appearance of Asiki on the market. ASIC does not need to be configured, it is easy to use, and this is what most miners need. For prototyping, ASICs use FPGAs, but programming them is the task of the manufacturer, not the miner.
However, with the growing number of ASICs in large mining pools, the so-called “attack 51%” threat appeared for various coins. Then the creators of these coins began to change the algorithms in the struggle for the decentralization of the blockchain, as mentioned above.
Now FPGAs are becoming more interesting for the average miner, due to the risks associated with using ASIC. Because ASIC Antminer S9 , which at the peak of popularity cost $ 5,000 on the secondary market, can now be purchased for $ 200 with a power supply.
FPGA vs ASIC
The first thing to note is that developing FPGA is much easier. Unlike FPGAs, the ASIC design begins with a completely empty table. It does not mean that everyone will adjust the chip for mining at home. But with a base and reading the experience of others (see below), the task is theoretically feasible.
On the FPGA, you start with a large array of logic blocks, PLL, embedded RAM, I / O buffers, (de) serializers, power distribution networks, and so on. The development of the ASIC itself starts from a lower level. This means that components must be purchased or manufactured as part of a library, or individually designed for ASIC.
The next big difference is the development cycle. Simple FPGAs can be built during the day or a couple of weeks for a moderately complex project. This is exactly the cycle: development -> release -> test -> fix -> development …
A single ASIC production cycle can take several weeks (months), after which you need to integrate and test it. After tests, bugs do not fix, it is too expensive.
ASIC technology provides higher speed and lower power consumption compared to FPGA. Differences in speed between the two methods easily reach 10 times or more.
- FPGA pluses: you can play yourself, suitable for a hobby, cheaper for one unit of goods
- Advantages of ASIK: faster, lower consumption, many offers on the market, working out of the box.
FPGA vs video cards (GPU)
GPUs are much more powerful than CPU's in both power and hashing / watt, but due to the inherent FGPA parallelism can be about 15 times more efficient.
In general, the FPDA output is such that they consume less electricity, can be reconfigured and designed independently if you understand microelectronics. But they have:
- high heat emission
- devices are not suitable for novice,
- to customize your own hands, you really need to look for materials.
Despite the higher price, ASIK will be more profitable. But for resistant to such development of coins, you can try the FPGA-miner.
Where can I buy FPGA in 2019?
The main FPGA manufacturers – Xilinx and Altera (Intel) – are located in the USA, making it harder to buy a card. Since the producers of these cards are units, it is impossible to directly purchase them to a retail buyer.
Major miners in Europe and Asia can also order cards through the American company SQRL or Cyprus COMINO, but this also presents a number of difficulties, for example, customs clearance.
Another solution – CrystalCore based on FPGA Xilinx UltraScale Plus – is offered by engineers of the Belarusian company AETTECH. The equipment is a cell with an immersion liquid, which contains from three to nine FPGA chips and other electronic components that serve the operation of these chips.
The average cost of FPGA chips varies from $ 3000-6000. The price of CrystalCore solution starts at $ 19,200, including all components.
Conclusion
FPGAs are able to provide flexibility and bring mining back to ordinary people like you and me. FPGA chips will allow you to mining almost any algorithm at any time.
Unlike ASICs, which require you to invest several thousand dollars in mining using a single algorithm, FPGAs can be a universal, comprehensive mining solution (like the GPU in the past).
Always conduct your own research and invest only at your own risk. We have made every effort to tell everything that we know about this topic. We may have simplified some aspects too much, but we hope that this article was a good presentation of mining with the help of FPGA.
I would like to know your thoughts, which you can share in the comments block below.
