Production of equipment for mining cryptocurrencies is a rapidly growing industry that has passed through certain stages of development over a relatively short period of time. One such step was the use of FPGAs, or FPGAs, to create hardware miners. The first such devices of course designed for bitcoin mining and existed for a short time, after which they were superseded by ASIC-mainers. One such device was reviewed here, for example.
But the era of FPGA mining doesn’t end there. Over the years, the number of cryptocurrencies has grown significantly, as has the number of hashing algorithms. Equipment manufacturers respond to the changing situation in this market by releasing more and more ASIC-based mining devices.
However, modern ASIC chips are created only for one algorithm, and if the cryptocurrency algorithm changes, it is impossible to modify the chip for the new algorithm. And this kind of algorithm change is quite common. Suffice it to recall at least the ongoing struggle of Monero with ASIC-mainers, or Vertcoin, the creators of which have changed the algorithm, taking their coin from ASIC-mining. Unlike an ASIC, an FPGA chip has the huge, indisputable advantage of adaptability and program flexibility, because it can be reprogrammed and continue to be used on a changed algorithm.
BlackMiner miners
Modern FPGA-based miners can be roughly divided into two categories. The first category, which can be conventionally called “for professionals”, includes typical FPGA boards with different interfaces, for the programming and maintenance of which you need to have a number of specific knowledge. The second category, “for the home miner,” includes ready-made devices with a user-friendly interface, which do not require additional knowledge to set up.
The second category of FPGA mining devices is represented by BlackBlock. The company currently produces and sells four models of miners:
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Blackminer F1 Mini, priced at $179;
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BlackMiner F1-single, priced at $1,300;
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BlackMiner F1, priced at $2,000;
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BlackMiner F1+, priced at $2,800.
This article discusses the cheapest and simplest BlackMiner family of miners – F1 Mini. Reading the small description on the manufacturer’s website, you will notice the phrase “No radiators and no power supply are included in order to reduce shipping costs”.. This means that to operate the product you need to prepare a power supply in advance. ATX units with PCI-e video card power connectors will fit. However, the board also has a connector for a normal DC 12V power supply, the main requirement for which is to provide a true 8A output.
Ordering and Shipping
For our customers we have prepared a special discount code for F1 Mini – bits.media. The code must either be entered in the order window or initially follow the link.
Delivery in the Russian Federation is made through “EMS Express” service. Using EMS as a courier company is convenient for the manufacturer, as other courier companies are now undergoing serious inspection and clearance at the Russian customs. To other countries, the miner will be shipped via UPS.
The packaging is pretty standard for such shipments. The FPGA customs declaration lists the miner as a “development board”.
Underneath the packaging is a rather hard cardboard box:
In the box itself, the board of the miner is packed in an anti-static bag, which is placed in a special tray formed from polyethylene foam. The top of the package with the board is covered with a lid of the same material. Such careful packing eliminates the possibility of damage to the miner’s board during transportation.
Physical Construction and Features
The miner in question consists of two parts. The front part is designed for the installation of cooling, which should not interfere with anything. That’s why there are almost no electronic components on the front end.
Under the yellow warning label is the FPGA chip.
The miner uses an FPGA from Xilinx Kintex-7 family, model XC7K325T. It is quite a powerful and productive chip with 326080 logical cells. The detailed specifications are as follows:
In the Kintex-7 family, this chip belongs to the middle segment both in terms of specifications and price.
The back side of the miner is undoubtedly more interesting in terms of its content.
At the right bottom of the board there is a connector for 12V PCI-e power. To the left of it is the ON-OFF switch, the connector for DC 12V power supply units and in the lower left corner of the reset button. There are two red 4-pin connectors on the top left side of the board, for connecting active cooling fans. In the center of the composition proudly shows a black board with a white inscription “Antminer. Many owners of Bitmain ASIC miners sincerely believe that this board is nothing but a control panel for Bitmain Antminer. However, this black board is just a single board BeagleBon Black
version 2.5, or BBB in common parlance.
Anyway, having the Bitmain branding on the single board itself is surprising, but not surprising that it was the BBB that was used as the control board for the miner. There are quite a few ready-made system solutions for this single board, including those in the public domain.
As mentioned above, the miner is shipped to customers without a cooling system and power supply. As a cooling tower cooler is suitable for Intel CPU LGA115X family. There are four holes on the front side of the board for its installation. However, it is noteworthy that there are four more holes near the FPGA FPGA chip. That is, it is possible to install a small passive cooling on the chip. It makes sense to use this type of cooling if you plan to place the board in a sealed, well-vented enclosure.
On the end of the board are two signal LEDs. The logic of their work is standard, used in many ASIC miners. If the green LED blinks slowly, about once a second, then all is well, if it is red, then there is a problem.
It is not recommended to turn on the miner without cooling. Pools and the hashing algorithm are already prescribed by default in the miner settings. Therefore, when powering up and plugging in the network with DHCP, the miner will start working right away.
The software component of the miner
The operating system and the software of the miner are located on the BeagleBon Black single board computer mentioned above.. As the operating system chosen Linux for ARM, there are no surprises.
Not the newest, but proven on many systems kernel 3.8.13. There is quite a lot of free RAM. In general, the conclusion is that the BBB for this model is more than enough miner, and instead of it could take another board, cheaper.
The main resources of the control board are consumed by the cgminer 2.3.3 adapted to work with FPGA. Linux systems have a “Load average” of 0.6, which is quite comfortable for a system of this class.
In the list of running processes you can see a number of programs and scripts, which can be seen on Bitmain miners, such as “monitor-ipsig”, “montorsd”, “monitor-recobtn”, “monitorcg”. As a result, we can conclude that not only the control board, but also the software components of Bitmain were borrowed.
In the screenshot above you can see that cgminer is running through a screen program and is named cgminer. In the console, you can connect to the screen and observe how the cgminer works.
Unfortunately, cgminer does not display much statistical information in the console.
The structure of the file system is quite typical of operating systems of this type:
Although if you look more closely, you might notice a couple of unfamiliar directories – fpgabit and sdcard – and their presence is no accident. This control board controls the FPGA, which in turn needs so called “bitstreams”, or bitstreams. Each algorithm needs its own bit stream, and since F1 Mini “understands” quite a few algorithms, it can store a lot of them in the internal memory of the miner. The developers of the device talk about seven bit streams that can be stored simultaneously. If the memory is full, but there is a need to add a new algorithm for mining, you will have to connect to the miner yourself and remove unused bitstreams.
In the screenshot above, you can see that there are five bitstreams and five configuration files for cgminer in the fpgabit directory. You can notice that the bit stream itself has a size of about nine megabytes. This is normal for the Kintex-7 FPGA used. As an example, the Cyclon V bitstream size is about four megabytes.
The sdcard directory only appeared in recent versions of the miner software.
This folder is an external SD-card mount point and is intended for storing bitstreams of only one algorithm Odocrypt, which at the time of writing is not used yet. This is the algorithm that will be introduced on DigiByte instead of Myriad-Groestl after July 19 and was originally made FPGA-friendly. The need to use the memory card separately is due to a change in the hashing algorithm every 10 days. That is, every 10 days the miner will have to change the bitstream. Accordingly, manufacturers plan to pre-generate a certain amount of them, which will not fit into the internal memory of the control board.
Mining
The user interface is accessible via a browser. As with other such miners, the main task is to find the device on the network and then access the found IP address with the browser.
All the basic information is on the start screen of the miner. However, the first thing to do is to go to the pool settings for mining. It was noted above that F1 Mini comes with the settings prescribed in it. So you can see something like that on the screen:
It is possible that in other F1 Mini there will be something else, but in this sample there were prescribed pools for the algorithm amoveo. The full set of algorithms available for the miner can be viewed and downloaded on a special page.
The screenshot above shows 18 algorithms as well as the main firmware for the control board – “Rootfs Linux Image”. The algorithms themselves are partially universal – for F1 mini the bitstream files designed for the older model of F1 Miner are suitable.
In the list, you can see the algorithms which have a hidden name. For example;in the screenshot above it is the Algo7 algorithm.. Miner developers deliberately hide the name of some algorithms. As they themselves clarified, the point is that some communities of certain cryptocurrencies do not like it when their coin starts to be mined with FPGA. That’s why the name of some algorithms are hidden and reported only to the buyers of devices. By the way, for a preliminary estimate of the profitability of miners the developers offer to read a special page
on their website.
Unfortunately, there is no yield information for F1 Mini, but the overall picture is quite realistic.
The algorithms and file system are updated in the same menu.
After the archive with the algorithm files is downloaded, the miner will automatically restart, and after that all the downloaded algorithms will be available on the pools configuration page in the dropdown list.
The “Customize the fan speed percentage” option at the bottom of the screen, set to 0%, is vital.. As practice has shown, there is some bug in the current version of the firmware. If you do not set this option, mining will not start. It is related to the error of recognition of the connected cooling fan. However, it is likely that other instances of F1 Mini will not show this error.
Testing of F1 Mini mining was performed on its own pools made based on the decentralized pool – p2pool. Such a choice is not accidental. Stratum of decentralized p2pool is not quite standard due to the peculiarities of the pool itself. So it is always interesting to check whether the next new miner is able to accept different interfaces for mining;
From the list of algorithms, three were chosen – Phi2 (Argoneum coin), Tribus (Denarius coin) and Lyra2rev3 (Vertcoin coin). When this article was written, another GPU algorithm was released – Honeycomb (Beenode coin). All four algorithms were previously considered algorithms exclusively for the GPU, which showed good returns on them. Let’s take the Tribus algorithm as an example to look at setup and mining.
After configuring the miner, after some time, information appears on the Miner Status page.
The screenshot above shows the results of mining on the Tribus algorithm. The average hash rate for three days was 236 Mh/s, although the manufacturers’ F1 Mini specifications page indicates 244 Mh/s. The small difference can be explained by the not very stable Internet channel at the test bench location.
The power consumption of F1 Mini when mining with the Tribus algorithm at the default frequency (490 MHz) is 68.2W.
To test the overclocking potential the default frequency of 450 MHz was increased by 10% to 540 MHz
Power consumption increased from 68.2 to 73.1 watts, an increase of 7.1%.
At the same time, the hash rate increased from 236 Mh/s to 262 Mh/s by 11%, and the temperature on the FPGA chip increased from 35 to 38 degrees, by 8.5%. As with any other miner, F1 Mini should be overclocked carefully, controlling parameters and understanding what you’re doing. As a mandatory recommendation, normal chip cooling.
It is most interesting to compare the mining efficiency on different algorithms of GPUs from different manufacturers and the F1 Mini miner in question. For this comparison we took the four algorithms mentioned above – Phi2, Tribus, Lyra2rev3 and Honeycomb.. In addition to F1 Mini mining was conducted on AMD Vega64 and Nvidia 1060. The results were summarized in a comparative table
Algorithm
AMD Vega64
Nvidia 1060
F1 Mini
hashrate
energy
hashrate
energy
hashrate
energy
Phi2
11.3 Mh
220 W
5 Mh
120 W
7 Mh
70 W
Tribus
99 Mh
220 W
60 Mh
120 W
237 Mh
68 W
Lyra2rev3
98 Mh
220 W
30 Mh
120 W
20 Mh
62 W
Honeycomb
49 Mh
220 W
30 Mh
120 W
31 Mh
57 W
The results do not need any comments and allow you to evaluate the effectiveness of FPGA mining in comparison with GPU mining. It makes sense that different algorithms have different performance on different equipment.
In conclusion
In the end it is worth noting that the device turned out to be very interesting. The implementation of multi-algorithm mining on FPGA with user-friendly interface is quite good.
Blackminer has a big community, but it is focused mostly on Discord. In Telegram, especially in the Russian-speaking segment, the manufacturer is not represented. Especially for the development of the Russian-speaking community there is an open group.
For those who are interested in FPGA mining and want to buy F1 Mini we remind that specially for bits.media users there is a discount code – bits.media. The code should be either entered in the order window, or initially follow the link with this code.