All About BItcoin and Litecoin mining and other alternative crypto currencies
Last month we’ve had the opportunity to do some remote performance tests of one of the earlier prototypes of the A2BOX Scrypt ASIC miners and recently we were able to get our hands on one of these powerful miners to do a hands on review of the final product being shipped to customers from MinerEU. These miners are based on the 28nm Innosilicon A2 Scrypt ASIC chips and have 48 of them placed on 6 separate modules able to provide a total hashrate of about 84-86 MHS. The device comes with a built in power supply and a Raspberry Pi controller with a web based control panel, so it is ready to be connected and you can immediately start mining with it.
The power consumption mentioned in the specifications of the miner is 750W and the power supply you will find inside the case is GameZone GX1100M, apparently rated at 1100W 80Plus Gold certified. We could not find that much information about these power supplies as they are apparently a Chinese brand, but a good quality one judging from the specs and the performance they offer – supposedly providing 90% efficiency. We are going to be comparing these power supplies to other well know brand model in terms of power usage and efficiency, but we are not going to be focusing on that here. The review of the miner will be done with the ATX power supply that you get the Scrypt ASIC miner with and as we’ve already mentioned the GameZone GX1100M does a great job in powering the device. The specific model should be capable of handling peaks of up to 1300W as we understand and it uses a modular design, though not fully modular.
You can see that inside the case of the miner there are 6 modules with big aluminum heatsinks. Each module has 8 chips and there are heatsinks both on the back of the PCBs as well as on the front side directly placed on the A2 chips for better cooling. The fact that the device uses 28nm chips and has large heatsinks on both sides along with serious airflow ensures that the miner runs pretty cool, even with the not so low power usage of the device. We’ll get back to the cooling system and its performance and the operating temperatures in a bit when we start talking about the tests. What does make a very good impression is the fact that the miner is very sturdy and well built and you would expect nothing less for a piece of hardware that is so expensive.
The A2BOX Scrypt ASIC miner comes in a standard 4U case, so you can say that it is ready to go directly into more serious mining farms that use racks in data centers for example. The device itself does look a bit like a server because of the case and because of the noise level you will get from it. We’ve seen noisier miners, but you cannot call a noise level of about 67 dBA at a distance of 1 meter from the device very silent either. The miner uses three server grade 120x38mm Nidec TA4500DC fans for the cooling and they do a great job with the noise not being considered at all. What you should be well aware of is that this miner is not a great choice to have at home in your living room or bedroom to mine 24/7, it is best suited for use in a well ventilated dedicated room for mining hardware or a more serious mining farms.
Taking a look at the power usage of the device we can see that it needs about 825W of power from the power socket, and if we take into account the 90% efficiency of the power supply the actual power consumption of the hardware should be about 750W. You are however going to be paying for the 825W of power as the difference is what gets wasted as heat during the conversion inside the PSU. Since currently Innosilicon A2 Scrypt ASIC chips are still the only ones that are based on 28nm process they are also the most power efficient solution available on the market in the form of a Scrypt ASIC miner. The drawback is that the miners based on these chips are more expensive to produce and that affects the end user price as well, but at the moment reaching the same hashrate with alternative solutions that are based on 55nm chips would come with about 3 times higher power consumption.
Here are two thermal images we took of the A2BOX miner working and as you can see the operating temperatures of the hardware are pretty low, we were actually surprised after we were used to seeing higher temperatures with the 55nm ASIC miners. The three big cooling fans push air inside the case thorough the large aluminum heatsinks and the hottest temperature we’ve measured was just at about 42 degrees Celsius. This is with an ambient temperature of 25 degrees C, so there could be some variance and you should be careful not to place the miner in hot areas without good ventilation.
Now, we’ve mentioned that the A2BOX Scrypt ASIC miner comes with a built-in Raspberry Pi controller and it also has a web-based control panel installed, so you can easily access, control and monitor the device. The main screen offers quick and easy options for you to setup the miner’s network settings, mining pools, operating frequency, basic stats etc. As we’ve said it is more basic solution, but has all of the important stuff in a single page, so it is very easy to use. As a backend the miner relies on a special version of cgminer 3.9.0 with support of the A2 scrypt ASIC chips. The web interface does allow you to set the operating frequency for each of the 6 modules independently, though you have only two options available – 14.88 MHS per board at 1200 MHz or 12.40 MHS at 1000 MHz.
There is also a more detailed real-time status monitor available that can help you monitor the performance of your device and if needed to take some steps to improve the results you are getting or change some settings for the best possible results. The results you see on the screenshot above are from the miner running at the higher clock of 1200 MHz. With our initial tests of the earlier prototype we’ve seen that it has produced a bit more HW errors that we’ve liked, but now the final production units does seem to perform much better and with far less HW errors. Do note that for ASIC decides it is normal to get some HW errors over time, however you should find the best balance between performance and HW errors in order to maximize the useable hashrate.
If you would like to have a bit more advanced and user friendly web-based control of your miner there is a solution available, a Scripta-based image with A2 chip support. You can download and put that image on another SD flash card and replace the one you get by default with the miner installed in the RPi controller. We do recommend to keep the original SD card with the official image intact just in case and as a backup and not to overwrite it with another image.
But what about performance, well it is also improved and higher than what we were getting in our earlier remote testing of the prototype device. As you can see on the screenshot above taken from the LTC Rabbit for a period of 48 hours the hashrate remains very stable and averages somewhere in between 85 and 86 MHS poolside. The locally reported hashrate is a bit higher, though the poolside reported rate from the miner’s web interface is also about 86 MHS. Testing the device at other pools hash also shown us an average in between 85 MHS and 86 MHS pool side hashrate with the miner running the A2 chips at the higher 1200 MHz operating frequency.
What can we conclude about the 86 MHS A2BOX Innosilicon A2-based Scrypt ASIC miner is that it definitely delivers what you are promised. You get a well designed and built device that comes with absolutely everything that you need to start mining immediately, no need to buy something separately to make it work such as a power supply for example that can add to the expenses that need to be calculated when you consider what is the expected return of the investment. The miner is very power efficient for the hashrate it offers when you compare it to what the alternative 55nm solutions do provide at the moment. The miner is not very silent, but the proper cooling is way more important and the fans do a great job in keeping the ASIC chips cool and operating with low error rate.
All seems good so far, but there is a catch and one thing that is not that great and this particular thing is the price of the miner. Currently the standard price of the 86 MHS A2BOX Scrypt ASIC is $10200 USD, so out of the budget for many miners and a more interesting option for more serious miners and larger mining farms. We have some good news for the people that are actually interested in buying this device, we have a special promo code that will get you $700 USD off the standard price, so you will be able to get the A2BOX Scrypt ASIC for $9500 USD. All you have to do is enter the following coupon code when you add the device in the shopping cart 9500A2BOX_cryptomining-blog to be able to take advantage of the promotional price. There is also another alternative option, a smaller and more affordable in terms of price version of the A2BOX miner – the 28 MHS A2Mini Scrypt ASIC available for a price of $3900 USD at the moment. Unfortunately there are still no very affordable solutions that use just one or two A2 chips inside a compact and very power efficient device while still producing a few MHS available that would be of interest to the average small crypto miner that might be interested in getting a very affordable Scrypt ASIC miner.
We have been testing the 27 MHS GAWMiners Falcon Scrypt ASIC Miner, the unbranded version, which is essentially the same as the first batch of ZeusMiner Thunder X3. The later batches have been branded with red GAWMiners cases and have some fixes and improvements from the initial design, addressing most of the small details that needed fixing from the first batch. Things like optimized the case and cooling, providing space for integrated power supply and so on are now available in the new design, so we are not going to be talking much about the small flaws in the first batch as they have apparently been resolved in the new and improved batches.
GAW ships their Falcon Scrypt ASIC miners bundled with a ZenController by ZenMiner, essentially a Raspberry Pi with an image designed to provide support for the miner and offer cloud-based control of the device directly through a web site. This makes it easier to monitor and control your miner remotely without having to have direct access to the IP of the miner, be on the same network, or use remote connections etc. A convenient way to get started without having to rely on a PC to connect and control the miner, though the Falcon does have a USB port and you can use it with a direct connection to a computer as well. If you are not happy with the ZenOS there is also the option to use a different RPi image with support for the Zeus ASIC chips, there are already a few alternatives available.
The cooling of the Falcon miner is done with two 120mm fans (HFD12038M12BL), the larger type that are 38mm and not 25mm and these are quite powerful and not so silent. But that is to be expected considering the power consumption of the miner, and is something that pretty much all big ASIC miners that provide a lot of hashpower have in common. Unfortunately we could not find details about the specifications of the fans used, but in general it is not a good idea to try to replace these fans with ones that are more silent as that may lead to not so good cooling efficiency and the device overheating. The cooling of the miner is designed in a way that the fans are pulling the air from inside the case and the airflow goes through the large heatsinks, an effective solution from our tests, though the chips still do get quite hot.
Here is a look at the noise level of the miner running, measured at 1 meter distance from the device – almost 68 dBA. Not very silent, but we have seen other big miners that have been even noisier than that. What is clear however is that you will not be willing to put this miner in your living room or bedroom for 24/7 mining as the noise level is not suitable for that, you would want to use the miner in a room where the noise is not an issue and the air circulation is good.
Looking at the specifications of the Falcon Scrypt ASIC miner you can see that the power consumption on GAW’s website is 1040W, so apparently a good quality 1000W power supply is recommended to be used with the device. We did measure the power usage of our unit and you can see the results above, but generally speaking a 1000W 80 Plus rated ATX PSU is a good idea to be used. Our test has shown that the actual power usage of the miner is about 916W. The fact that we are using a more powerful 80 Plus Platinum power supply gives us very high efficiency of over 94% at this serious load, so the total power consumed at the wall is roughly 970-975W.
Inside the Falcon miner you can find 4 boards with 32 Zeus Scrypt ASIC chips on each. These are attached to large aluminum heatsinks, though the contact point is not the top of the chips, but instead the back of the PCB. This is the easier approach that many ASIC miners use, especially if you have boards with a lot of smaller chips on them, while if you have fewer larger chips they usually have a heatsink on top of the chip. This cooling design does work well, though often with the back contact point the operating temperature of the chips is higher, but apparently no problem for the 55nm Zeus chips.
We did take some images with a thermal camera of the Falcon miner in order to have a better idea on the cooling efficiency of the device. On the outside the Falcon is pretty cool with the hottest areas barely getting up to about 42 degrees Celsius, so the cooling method used is doing very well.
We’ve opened the case of the miner to take some thermal images of the inside, and as you can see on the left image, the four big aluminum heatsinks remain very cool at about 30-35 degrees Celsius while the fans are pulling a lot of air though them. Looking at the boards with the ASIC chips they do seem a bit hotter as to be expected, the chips are pretty hot as the design of the miner uses the back of the PCB to transfer the heat to the heatsinks as we’ve already mentioned. Temperatures of about 60-70 degrees Celsius are apparently something that is not a problem for them, though you should be careful not to get the temperatures much higher like for example leaving the miner to work with an open case for some time. The power modules of the boards do seem cooler than the ASIC chips, though they do get a bit hot as well.
Time to talk a bit about the performance you can get from the 27 MHS Falcon Scrypt ASIC. These miners are rated at 27 MHS or more from GAWMiners and they do manage to deliver even slightly higher average performance when you run them at the recommended operating frequency of 328 MHz. The minimum average hashrate we got at the LTC Rabbit mining pool for a period of 24 hours was 25674 KHS and the maximum was 29332 KHS with an average across the whole day of 27882 KHS. Trying out the Scrypt ASIC miner at the ScryptGuild mining multipool where you mine altcoins and get payments directly in BTC has shown us very similar performance – the average hashrate poolside was about 27738 KHS.
Looking at the locally reported hashrate when running the cgminer 3.1.1 with ZeusMiner support also shows an average performance of 27.5 MHS as well, looking at the reported WU number that is recommended to be used for judging the actual local hashrate.
So we can conclude that the 27 MHS GAWMiners Falcon Scrypt ASIC miner is really delivering what is being promised and the power rating, although a bit high, is also true as claimed (actual power usage is a bit lower with a good quality PSU). The unbranded Falcon miner from GAW did have some small design flaws that we have noticed, but we’ve seen pretty much all of them being addressed in the newer design that the branded Falcons (with red cases) use. What still seems to be missing though are the rubber feet on the bottom of the case, but you can easily add these yourself, so not much of a problem anyway. With the current price of $1929.95 USD for the latest batch the Falcon does look quite attractive with the performance it offers, though do not forget that you will also need a 1 KW ATX power supply as the miner does not come with a built-in one, so that is some extra cost if you don not have the PSU already. The Falcon using the Zeus 55nm chips at the current prices is an attractive choice as the main competition, currently also shipping hardware, that uses 28nm Innosilicon A2 chips with lower power consumption is about twice as expensive in terms of price for the same hashrate.
GAWMiners has just released some interesting information, their plans to start offering what they call the world’s first 500 MHS Scrypt ASIC miner, and on top of that it will be powered by sub-1000 Watts power supply. The Vaultbreaker and its brother, the smaller 250 MHS Vaultbreaker Mini – for the compact enthusiasts – are the first of a new line of Scrypt ASIC machines GAW will release. Shipping time for the first batch is apparently planned for the end of Q3, or early Q4, with the company promising that they will try to beat the KnC Titan to market. The pre-orders for the new Scrypt ASIC miner should start today for existing customers and after that, they will be opening up the doors to the public at large on the 24th. The price for the pre-order is currently set at $8999.95 USD or $4999.95 USD for the Mini, so cheaper than the other competing products that do currently promise lower hashrate. There is no information what the ASIC chips inside the miner will be, but with this kind of performance promised at sub 1000W power consumption you can guess that we are talking about 28nm chips or even less…