Released in the spring of Antminer S9 was greeted by a rather contradictory - despite the impressive performance and energy efficiency, he surpassed all his predecessors and competitors one indicator - the impact on the auditory nerves of its owner. Noise can be partially compensated by replacement of regular fans for more silent and still for home mining the model is applicable with limitations.
Having a decent amount of negative feedback, the company Bitmain has begun to develop a miner that is designed to work at home. And so, in the last week of August, appeared in the sale of Antminer R4. In it, the manufacturer has changed some of his habits, but the main objective was to reduce noise while maintaining performance - has been solved successfully.
Receiving and unpacking
New domesticated Antminer came to me on September 5 in support of the EMS. Shipping from China took a little more than a week.
Seeing the impressive size of the box - twice more than "odd" of the Ants, I thought that it along with a miner in some way was the power supply or something else useful, but the courier I it immediately dissuaded. Actually, the miner and the power supply is somewhat dispersed on the way and arrived the same day.
Of course, I was curious what is in this roomy box. But the delivery, like the S9, turned out to be extremely ascetic. In addition to miner, it was a piece of paper containing brief information about designs of miner, in terms of energy and connection, and also describes what not to do with the miner, and what to do if you did what not to do.
According to the instructions, I have long and carefully shook the miner, but all was quiet. Radiators and other items remained in place. Not rattled and rigidly fixed fee hashing.
Design features
After extraction Antminer R4 out of the box, immediately became noticeable its difference from all previous models of the company. With less one-third Hasrat compared to the S9, it far exceeds in size the older brother, its dimensions are 512210 cm compared to 3513.515 cm at S9. The case is made of bonded studs steel sheet with a thickness of 1.5 mm, and disassembled into three parts. The body does not walk and does not bend.
While the S9 you can disassemble any object caught by hand Phillips screwdriver, for disassembly of the R4 need to take the tool thinner and patience - screws in it much more.
Assembled miner resembles a small piano, under the lid which is key boards are hashing. This interesting form occurs from the more massive cooling system, which follows.
Antminer R4 in everything except housing and ventilation, very similar to its "big brother" - S9. It is based on the same 16-nm chips BM1387 energy efficiency is about 0.1 W/GH/s control module BB Board and web interface are completely identical. Mining IN BMminer version 1.0.0 introduced in the late batchas S9 - is a closed modification of cgminer from Bitmain.
Unlike S9, within R4 are only two boards hashing, also for 63 of the chip, but they have a more elongated shape and the chips are not located in six rows, and three. This is done to improve the efficiency of blow - in R4 it is not longitudinal, as in other Antminer, and transverse.
The performance of the device with factory default frequency of 600 MHz stated in 8.6 GH/s with power consumption from the outlet is about 960 watts. The wiring boards is somewhat different from the S9, but most components are identical.
Boards fixed horizontally into the housing grooves, which are provided with plastic pads to absorb vibration. In case they are fixed by means of four notched metal brackets with screws, one of which also presses the interface cables circuit boards hashing.
Noise and cooling
Now we come to the key difference Antminer R4 from all the other ASIC miners with air cooling. Me from the beginning surprised by the large lattice box, which occupies two-thirds of the volume of the device. It was there hiding in the longitudinal tangential fan. This type of fans used in industrial ventilation and air conditioning. In electronic devices is a rare visitor, and in equipment for mining in my memory, these fans are applied for the first time. This is not surprising - for the miner important low cost and compactness, and tangential cooling fan several times more expensive than the two-axis and takes several times more space. In addition, it requires a more complex channel for the air flow direction.
All this complicates and increases the cost of construction ASIC miner, which is not very good for high volume devices that are hosted in data centers. But for the home miner, which usually takes on one or more Usikov, dimensions are not so important, but the dignity of a tangential fan is easily offset its disadvantages.
First, because the longitudinal blades the full length of the housing, this fan creates more even air flow with less pressure, while the classic "tube" with two axial fans on the ends are most effectively cooled the chips closest to the blower fan, the rest goes to the heated air. For any uniform cooling required to create a denser stream of air with accompanying sound effects.
The maximum speed of the tangential fan of unmarked, established in R4 - around 3000 rpm, but for effective cooling at room temperature to 25 degrees is sufficient 60% fan speed (~1 800 rpm). At such speed miner noise is not more than the average laptop or office system unit that was presented to the miner MIC shows 35-40 decibels.
With the background noise of an open window overlooking the courtyard, his rustle is lost in the distance of about two meters. Noticeable the whistle appears if the rpm is above 2000 per minute, and at full speed the fan produces a dense characteristic noise about 50-55 dB, but heard from the next room with the door closed. However, the inclusion of the fan at full speed may be required only when the room temperature is above 35 degrees.
Power supply APW5
Specifically for Antminer R4 manufacturer released a new model of power supply - APW5. It is designed to power two Antminer R4, so it is more powerful than all previous PSU from Bitmain. Its nominal capacity at a voltage of 220 V is 2600 W, and has a mode for the U.S. market - 1300 W at 110 V. it has two single 6-pin connector control Board and 4 bundles for 3 connector Board hashing.
A significant reserve of power allows you to connect two Antminer R4 and leaves the potential for overclocking. It can be used with the miners of previous generations, for example, a single unit connectors and power "feed" 7 pieces Antminer S1.
In APW5 instead of the traditional server high-speed 40mm PSU fan, a 120 mm fan which is almost inaudible.
Perhaps the only drawback of this unit is for home use - bare output contacts. Therefore, it should be kept out of reach of children.
Wiring and start-up
The process of connecting and running Antminer R4 are identical to those described for the S9, so no repeat needed. Attach half of the connectors from the PSU, LAN cable and switch on. As soon as the miner gets the address from the router, go to the web interface and set your settings for the pool.
After this it remains only to monitor the process temperature, and if necessary, adjust the fan speed. However, at a stable temperature in the room can be left "on automatic". Usually the fan runs evenly and quietly, small speed changes in hearing are perceived.
As in the case of the S9, my miner showed somewhat less consumption specified by the manufacturer despite the fact that the hash rate is close to the declared. At first I looked askance at the meter, but after checking the consumption room counter, made sure that the device is wrong in the worst case a fraction of a percent. However, in my home is somewhat reduced mains voltage is 220V, it is 210-212V.
Cross air blast circuit boards tangential fan showed the efficiency at an average room temperature of about 25 degrees, on the default frequency and fan speed to 60%, the temperature of the chips is in the range of 80-85 degrees, and plat - 55-60 degrees.
The first conclusions
Within a few days of operation Antminer R4, he quietly rustled, without attracting any attention. Hash rate and the temperature remained within the limits required above. Looks like Bitmain is really able to produce ASIC-miner, without any exaggeration suitable for home mining. Perhaps a few thousand (or even tens of thousands) of these devices spread all over the world, and will not be a decisive argument in the decentralization of Bitcoin mining, but today Antminer R4 is the only retail ASIC-miner last generation that you can even put under the bed and forget about it.
Among the shortcomings can be noted only some cumbersome design, undisguised contacts of the power supply, as well as the hash boards, is not protected at least by a grid. Would not hurt to provide the power supply switch. However, these shortcomings do not seem significant.
To be continued