In few words: Customizable chips allowing end users to create their own digital circuits.
A field-programmable gate array or FPGA is an integrated circuit designed to be configured for a certain task by an engineer after manufacturing. It does not have the programming built into it during the production, so it can be modified and used in wide spectrum of industries including aerospace, high-performance computing and medicine.These integrated circuits are faster for some applications because of their parallel nature and optimality in terms of the number of gates used for a certain process.
This type of hardware is not an innovation for the experienced crypto miner (actually the first FPGA was manufactured in the early 80s by a company called Xilinx), but it was never widely adopted in mining mainly due to the following reasons:
· High price and scarcity
· Difficulty in setting up the configuration which is far beyond the programming skills of the ordinary crypto enthusiast.
· Rise of the ASICs
As I mentioned, FPGAs are designed so their integrated circuit can be configured by the user after the manufacturing process is completed. This makes them very similar to the GPUs/CPUs, yet much more powerful. The FPGA combine the power of the ASIC with the flexibility of the GPU, but it never reached mainstream popularity.
Enter the ASIC
The ASIC (The Application Specific Integrated Circuit) is also a type of integrated circuit, but designed to perform a specific task only. ASICs are pretty easy to use (basically plug and play) once configured by the manufacturer and in the early days of the crypto boom promised high returns of investment. ASICS are pricey too, but do not require special programming skills or additional hardware configuration. These advantages made them extremely popular among users.
FPGAs were doomed
Unlike the FPGA, however, the ASIC cannot be re-modified for another task making it basically useless once the most profitable coins on an algorithm make a fork.
This is the main argument for some people to think FPGAs can make a comeback.
Pros and cons
So, let’s take a look at the following comparison table:
Looks like the programmable boards have an advantage over GPUs and ASICs in only 2 of the 5 categories, but some consider these to be the more important in current market situation.
If you can switch between different algorithms and mine the most profitable coins only, you can guarantee yourself high ROI.
The problem is with the other two categories –user friendly and availability.
To map designs on an FPGA an engineer uses a Hardware Description Language (HDL), the most popular being VHDL and Verilog.
What programmers do is they write a Bitstream — program that tells the FPGA what to do and then load it on the FPGA board. Not a walk in the park !
Now the solution
There’s a group or programmers and crypto enthusiasts working on bitstreams for crypto mining (mainly using the Xilinx VU9P FPGA boards).
They created a company called Zetheron and sell the product on the official webpage http://zetheron.com/.
Zetheron Technology provides free software to mine cryptocurrency with off-the-shelf FPGA hardware. Zetheron Technology has no products for sale. Hardware must be purchased from 3rd party suppliers.
These 3rd party suppliers are mentioned on the Hardware tab on their page, but you can order already configured Xilinx boards (the Blockchain edition) from https://fpga.land/.
Unfortunately the first batches were sold out in a matter of hours and configured boards are still out of stock.
You can try ordering a device from the Xilinx or Bittware sites (details can be found on Zetheron page, but from what I saw they deliver in the US only. There is also an option though for a company called Mineority to host your FPGAs at their facility without the need to ship them to you).
To build your rig you will need a setup similar to the one used in GPU mining rings and also a bitstream software upgrade.
$3500 for a board (as per Blockchain edition prices in FPGA LAND)+ $450 in hardware components and modifications per card + Zetheron software upgrade = approximately $32k for an 8-card rig.
This is how a Xilinx Blockchain edition FPGA mining rig looks like:
It’s a lot of money, I agree, so test results are critical for us to evaluate if it is profitable to even consider buying these devices.
You can find all project-related information (including prices, test results, delivery specifics and upcoming batches) on the Bitcointalk here: https://bitcointalk.org/index.php?topic=3459858.0.
or you can check the Zetheron page for potentially profitable FPGA Mining Algorithms (http://zetheron.com/index.php/fpga-performance-profit/).
Disclaimer: I’m not involved in FPGA mining not related to any of the above mentioned groups or organizations. I wrote the article for the sole purpose to share knowledge with more people.