BlackMiner F1 mini review: FPGA mining

Cryptocurrency Mining | Review

Mining on the FPGA is experiencing a new dawn due to the struggle of cryptocurrency developers with ASIC miners. The article describes one of these devices – the Blackminer F1 Mini.

The production of equipment for mining cryptocurrency is a rapidly developing industry that has gone through certain stages of development in a relatively short time of existence. One of these stages was the use of FPGA, or FPGA, to create hardware miners. The first such devices by themselves were intended for the extraction of Bitcoin and existed for a short time, after which they were ousted by ASIC miners. One of these devices was considered for example here.

However, the era of FPGA mining is not over. Over the years, the number of cryptocurrencies has increased significantly, as well as the number of hashing algorithms. Equipment manufacturers are responding to the changing situation in this market, releasing more and more new mining devices based on ASIC.

However, modern ASIC chips are created only for one algorithm, and when the cryptocurrency algorithm changes, it is impossible to modify the chip for a new algorithm. And such a change in the algorithm is quite a frequent occurrence. It is enough to recall at least Monero’s incessant struggle with ASIC miners, or Vertcoin, whose creators changed the algorithm by taking their coin from the sphere of ASIC mining. Unlike the ASIC, the FPGA chip has a huge undeniable advantage — adaptability and software flexibility, since it can be reprogrammed and continued to be used on the changed algorithm.

Miners BlackMiner

Modern miners based on FPGA can be divided into two categories. The first category, which can be called “for specialists”, includes typical FPGA boards with various interfaces, for programming and servicing of which it is necessary to possess a number of specific knowledge. The second category, “for the home miner,” includes ready-made devices with a friendly interface, the configuration of which does not require additional knowledge.

Representatives of the second category of FPGA mining devices are BlackBlock devices. Today the company produces and sells four models of miners:

Blackminer F1 Mini, cost of 179$;
BlackMiner F1-single, cost of 1300$;
BlackMiner F1, cost of 2000$;
BlackMiner F1+, cost of 2800$.

This article discusses the cheapest and easiest miner of the BlackMiner family – F1 Mini. Reading a small description on the manufacturer’s website, you can see the phrase “No radiators and no cost.” This means that in order to use the product, you must prepare the power supply in advance. ATX units with PCI-e video card power connectors will do. However, there is a connector on the board for a conventional DC 12V power supply, the main requirement for which is to ensure an honest 8A output.

Order and delivery

According to the good old tradition, the manufacturer has prepared a discount code specifically for users of our site to receive a discount for F1 Mini – bits.media. The code must either be entered in the order window, or initially follow the link.

Packaging is quite standard for such items. In the FPGA customs declaration, the miner is listed as a “development board”.

There is a fairly hard cardboard box under the packaging:

In the box itself, the miner’s board is packed in an antistatic bag, which is packed in a special cradle formed from polyethylene foam. On top of the package with the board covered with a lid of the same material. Such careful packaging eliminates the possibility of damage to the miner board during transport.

Physical device and characteristics

Considered a miner consists of two parts. The front part is designed to install cooling, which should not interfere. That is why there are practically no electronic components on the front.

Under the yellow warning sticker, the FPGA chip is hidden.

The miner uses FPGA from Xilinx Kintex-7 family, model XC7K325T. This is quite a powerful and productive chip on 326080 logic cells. Detailed specifications are as follows:

In the Kintex-7 family, this chip belongs to the middle segment both in its technical characteristics and in price.

The back side of the miner is undoubtedly more interesting in its content.

At the bottom right of the board is a connector for connecting the 12V power supply of the PCI-e standard. To the left of it is a switch “ON-OFF”, a connector for power supply from DC 12V blocks and a reset button in the lower left corner. At the top of the board, on the left, there are two red 4-pin connectors for connecting active cooling fans.

In the center of the composition, there is a proud black card with a white “Antminer” lettering. Many owners of Bitmain ASIC miners sincerely believe that this board is nothing more than a control socket for Bitmain Antminer. However, this black board is only a single BeagleBon Black version 2.5 or on the BBB common people.

Be that as it may, the presence on the mainboard itself of the stigma from Bitmain is surprising, but it’s not surprising that the BBB was used as a control card for the miner. For this odnoplatnika there is a sufficient number of ready-made system solutions, including in the public domain.

As noted above, the miner is sent to customers without a cooling system and without a power supply. As a cooling tower cooler will suit the family of Intel CPU LGA115X. To install it on the front side of the board there are four holes.

However, it is noteworthy that there are four more holes near the FPGA chip. That is, it is possible to install a small passive cooling on the chip. Such cooling is advisable to put, if you plan to place the board in a closed, well-blown housing.

At the end of the board there are two signal LEDs. The logic of their work is standard, used in many ASIC miners. If the green LED blinks slowly, with a frequency of about once a second, then everything is fine; if it is red, then there are some problems.

It is not recommended to turn on the miner without cooling. The default miner settings already have pools and a hashing algorithm. Therefore, when you connect the power and turn on the network with DHCP, the miner will immediately start working.

Miner software component

The operating system and software of the miner are on the BeagleBon Black single-board computer mentioned above. Linux is selected as the operating system for ARM, there are no surprises here.

Not the newest, but tested 3.8.13 kernel on many systems. There is a lot of free RAM. In general, the conclusion suggests itself that the BBB for this model of the miner is sufficiently abundant, and instead of it one could take another board, cheaper.

The main control board resources are spent on the adapted for working with FPGA cgminer 2.3.3. The Linux load average for the “Load average” system is 0.6 on average, which is quite comfortable for systems of this class.

In the list of running processes, you can see a number of programs and scripts that can be seen on miners manufactured by Bitmain, for example, monitor-ipsig, montorsd, monitor-recobtn, monitorcg. As a result, it can be concluded that not only the control board was borrowed, but also Bitmain software components.

In the screenshot above, you can see that cgminer works through the screen program and is named cgminer. In the console, you can connect to screen and watch cgminer work.

Unfortunately, cgminer does not display a lot of statistical information in the console.

The file system structure is quite typical for operating systems of this type:

Although if you look closely, you can see a couple of unfamiliar directories – fpgabit and sdcard, and their presence is not accidental. This control board controls the FPGA, which, in turn, needs the so-called “bitstreams”, or bitstreams, to work.

Each algorithm needs its own bitstream, and since the F1 Mini “understands” quite a lot of algorithms, they can be stored in the internal memory of the miner a lot. Device developers 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, then you will have to connect to the miner yourself and delete unused bit streams.

The screenshot above shows that the fpgabit directory contains five bitstreams and five configuration files for them for cgminer. You can see that the bitstream itself has a size of about nine megabytes. For the used Kintex-7 FPGA this is normal. For example, the size of the Cyclon V bitstream is about four megabytes.

Catalog sdcard appeared only in the latest versions of software for the miner.

This folder represents the mount point of the external SD card and is intended to store the bitstreams of only one Odocrypt algorithm, which is not yet in use at the time of writing. This is the algorithm that will be introduced on DigiByte instead of Myriad-Groestl after July 19 and which was initially made friendly to FPGA.

The need to use a separate memory card 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 their specific volume, which does not fit in the internal memory of the control board.

Mining

The user interface is available through the browser. As with other similar miners, the main task is to find the device on the network, and then contact the found IP address using a browser.

All the basic information is given on the miner’s start screen. However, the first step is to proceed to the settings of the pool for mining. It was noted above that the F1 Mini comes with the settings it contains. Therefore, on the screen you can see something like this:

It is possible that in the other F1 Mini something else will be found, but in this sample there were prescribed pools for the amoveo algorithm. The full set of algorithms available for the miner can be viewed and downloaded on a special page.

The screenshot above shows the 18 algorithms, as well as the main firmware for the control board – “Rootfs Linux Image”. The algorithms themselves are partially universal – for F1 mini, files with bitstreams are suitable for the older model of the miner F1.

In the list you can see the algorithms that have the name hidden. For example, in the screenshot above, this is the Algo7 algorithm. Miner developers specifically hide the name of some algorithms. As they clarified, the fact is that some communities do not like certain cryptocurrencies when their coins are started to be mined with the help of FPGA.

That is why the name of some algorithms is hidden and reported only to device buyers. By the way, for a preliminary assessment of the profit of the miners, the developers offer to familiarize themselves with a special page on their website.

Unfortunately, there is no information on profitability for the F1 Mini, but the overall picture is quite realistic.

The algorithms and file system are updated in the same menu.

After downloading the archive with the algorithm files, the miner will automatically restart, and after that all loaded algorithms will be available on the pool configuration page in the drop-down list.

The option “Customize the fan speed percentage” included at the bottom of the screen with 0% set is vital. As practice has shown, there is some kind of error in the current firmware version. If you do not set this option, then mining does not start trivially. This is due to the recognition error of the connected cooling system fan. However, it is likely that this error will not appear in other instances of the F1 Mini.

The F1 Mini was tested on its own pools based on the decentralized pool – p2pool. Such a choice is not accidental. The stratum decentralized p2pool is not quite standard due to the nature of the pool itself. Therefore, it is always interesting to check how the next new miner is able to perceive different interfaces for mining.

Three algorithms were selected from the list of algorithms – Phi2 (Argoneum coin), Tribus (Denarius coin) and Lyra2rev3 (Vertcoin coin). When the article was written, another GPU algorithm was released – Honeycomb (Beenode coin). All four algorithms were previously considered algorithms exclusively for GPUs, which showed good profitability for them. Setting and mining consider the example of the algorithm Tribus.

After setting the miner, after a while the 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 on the page describing the F1 Mini features, manufacturers indicate 244 Mh / s. A slight difference may be due to a not very stable Internet channel at the location of the test bench.

The power consumption of the F1 Mini during mining on the Tribus algorithm at the default frequencies (490 MHz) was 68.2 W.

To check the overclocking potential, the default frequency of 450 MHz was increased by 10% to 540 MHz

Energy consumption increased from 68.2 to 73.1 watts, by 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%. Accelerating the F1 Mini, like any other miner, you need to do it carefully, controlling the parameters and understanding what you are doing. As a mandatory recommendation – the normal cooling of the chip.

The most interesting thing is to compare the effectiveness of mining on different algorithms for GPUs from different manufacturers and the F1 Mini miner under consideration. For such a comparison, the above four algorithms, Phi2, Tribus, Lyra2rev3 and Honeycomb, were taken. In addition to F1 Mini, mining was carried out on AMD Vega64 and Nvidia 1060. The results were summarized in a comparative table.

The results obtained in the comments do not need and allow us to evaluate the effectiveness of mining on the FPGA in comparison with the GPU mining. It is logical that different algorithms have different efficiency on different equipment.

Finally

In the end, it is worth noting that the device turned out very interesting. The implementation of multi-algorithm mining on FPGA with a user-friendly interface turned out to be quite good.

Blackminer has a large community, but it is mainly concentrated in Discord. In the Telegram, especially in the Russian segment, the manufacturer is not represented. An open group has been created specifically for the development of the Russian-speaking community. For those interested in FPGA mining and those who want to buy F1 Mini, we remind you that a discount code – bits.media was created specifically for bits.media users. The code must either be entered in the order window, or initially follow the link with this code.