All About BTC, LTC, ETH mining as well as other alternative crypto currencies
Innosilicon still has not made any release of the source code of their cgminer fork with support for the A2 Scrypt ASIC chips, what you get with their A2 Terminator Scrypt ASIC devices is a Raspberry Pi with a preloaded cgminer and simple web interface to control the device. The standard web interface however is a bit limited in the supported operating frequencies – 1000 and 1200 MHz. The recompiled cgminer does allow for a few more operating frequencies to be used, however they are not selectable by default through the web interface of the miner. Some time ago there was a modified image released by a user called Emdje that supposedly allowed more overclock options. However it has turned out that it was not really functional as even though you could select operating frequency at steps of 5 MHz the cgminer did not accept these values and instead defaulted to some of the supported frequencies.
Back when we first had the chance to do a remote test of a A2BOX Scrypt ASIC miner we have discovered that the only supported operating frequencies by the Innosilicon A2 Terminator Scrypt ASIC miners are: 1000, 1080, 1100, 1200, 1280, 1300 and 1400 MHz. This is why we have made a modification to the standard RPi image that ships with the A2 miners, so that you can quickly and easily add the supported frequencies to be selectable from the web interface of the miner. This should allow you to squeeze some more extra performance from your device, regardless if it is the smaller 2 module or the large 6 module ASIC model, as our tests have shown that most of the miners should be able to work pretty well at up to 1280-1300 MHz up from the maximum of 1200 MHz that you have by default. Below you can download the modification we have prepared along with the instructions on how to update your miner, so that you get the extra OC options available.
How to login to your miner via SSH/SFTP using putty/WinSCP:
– username: pi
– password: innosilicon
Where to find the miner and web interface:
Replace the index.php file with the following modification:
– modified index.php
All that is left is to refresh the webpage with the miner interface and you should see the new options for operating frequencies available in the dropdown boxes for the A2 modules. For the smaller miners you need to select just the first two frequencies as you can see on the image above, for the large A2 miners you need to set all of the six frequencies. Do note that each of the modules can operate at a different frequency, so experiment and set the best frequency for each one that gives the lowest HW error rate and optimum performance.
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 at MinerEU. 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.
Thanks to our friends at MinerEU we were able to get remote access to test an early prototype of a A2BOX Scrypt ASIC miner. These miners us the new 28nm Innosilicon A2 Scrypt ASIC chips, 48 of them on 6 modules with each chip running at 1.5M with about 10W power consumption. The total hashrate of the complete miner is 72 MHS and can be further overclocked up to about 80 MHS or even more. Do note that the tests below are ran on an early prototype of the miner, so the final products tat customers will receive will be improved and should handle even better. In fact after finishing the tests and reporting our findings there were apparently already some improvements on the software part that should improve the results people that get the final product will be getting. We are going to be doing some more tests probably later this week of the final production units to check the progress, so stay tuned for more interesting information. For the moment we are only able to provide some first impressions and performance results from our remote access testing. We are going to try to also do a hands on review later on when we are able to get our hands on the actual hardware.
The miner itself is contained in a 4U case and aside from the 6 modules with the ASIC chips it also has a power supply inside the case as well as a Raspberry Pi controller with the software to control the miner. The software itself is a modified version of cgminer 3.9.0 with support for the Innosilicon A2 Scrypt ASIC chips and by default it is only a console only version of the miner, though the unit we tested also had Scripta installed to make it easier to monitor and control the miner. In overall things were running pretty smooth and easy with the cgminer in the back and Scripta as a frontend, though we’ve noticed some things that could be improved and hopefully they will be in the final miners that will be shipped to people that have ordered them. The 72-80 MHS A2BOX miners are pretty big and expensive at $12000 USD each, so they are not going to be accessible to all, however we may also get smaller units with 1 or 2 modules available as well that should be slower in terms of hashrate, but also more affordable and easier to get by miners that have a smaller budget for hardware.
The default operating frequency as per the A2 chips specifications is 1 GHz with a 1.5 MHS hashrate per chip running at that frequency, though the chips should be capable of 1.1 GHz with 1.65 MHS and 1.2 GHz with 1.8 MHS per chip. Increasing the operating frequency will bring up the power consumption and the heat generated, so proper cooling gets more important in order to actually get higher performance. The modified cgminer 3.9.0 with support for A2 on the Raspberry Pi actually allowed us to set a frequency of 1000, 1080, 1100, 1200, 1280, 1300 and 1400, if set to over 1400 MHz or under 1000 MHz defaults to 1000 MHz. Another good thing is that you can set individual frequency for each module, so you can find out if any of them can work fine at a higher frequency an other at low for optimum performance. It would be good however if a finer grain frequencies could be set by the user as currently the steps you can set in terms of operating frequency are pretty high.
Here is how things looked at 1200 MHz operating frequency of the miner, pretty much the highest one that is worth running the miner at. Scripta is reporting 87 MHS local hashrate and at the pool (scryptguild) we are getting about 80 MHS average, so pretty much what is promised as achievable in terms of overclocking. Do note however that two of the modules are running at lower hashrate as compared to the others and we have found the reason for that is some cores on the chips withing the two modules were not fully functional. Do remember however that here we are testing an earlier prototype of the miner, so it is expected that some things might not be working perfectly, though the good thing is that cgminer reports that and if you have similar problem you will be able to easily notice it when running the miner. We suspect that the reason for getting significantly higher number of HW errors on these two particular modules is also a result from that fact. But even in that situation we are still getting pretty good results when overclocked to 1200 MHz, even with higher than recommended number of HW errors. We got a notice that further optimizations have been made to reduce the HW errors, so the final products should be handling better.
Example output for module 3, 410 active cores out of 432:
[2014-05-08 13:50:02] spidev0.0(cs3): Found 8 A1 chips
[2014-05-08 13:50:02] Found chip 1 with 52 active cores
[2014-05-08 13:50:02] Found chip 2 with 51 active cores
[2014-05-08 13:50:02] Found chip 3 with 53 active cores
[2014-05-08 13:50:02] Found chip 4 with 42 active cores
[2014-05-08 13:50:02] Found chip 5 with 52 active cores
[2014-05-08 13:50:02] Found chip 6 with 53 active cores
[2014-05-08 13:50:02] Found chip 7 with 54 active cores
[2014-05-08 13:50:02] Found chip 8 with 53 active cores
[2014-05-08 13:50:02] Found 8 chips with total 410 active cores
Going higher in terms of overclocking brings up the local hashrate, however it also reduces the poolside one due to lower efficiency of the chips as more HW errors are being generated. So for example at 1280 MHz we were getting about 92 MHS local hashrate, but just 72 MHS poolside, clearly showing that there is no point to go higher than 1200 MHz, even when cgminer allows us to set the frequency up to 1400 MHz. Going a step lower to 1100 MHz we’ve got about 81 MHS local hashrate and about 77 MHS poolside, so at that frequency we are getting a lower difference between the local and the poolside hashrate than at 1200 MHz. Going one more step down to the default frequency of 1000 MHz (the minimum allowable by cgminer) we’ve managed to get about 72 MHS local hashrate and about 65 MHS poolside, so it seems that 1100 MHz seemed the optimal one where you are not pushing the chips too much. We have noticed that even at the lower operating frequencies the number of HW errors of the two modules that had some of their cores not properly working were still at more than 10% which is a value that is a bit too much for an ASIC device. So it seemed that the problematic cores were indeed the cause of us getting more HW errors and not pushing the chips to a higher frequency and with all of the chips properly working the local and poolside hashrate should increase a bit more than the one we’ve managed to get out of the early prototype that we were testing here.
In short, the new A2BOX miners based on Innosillicon A2 Srypt ASIC chips do seem to work quite good and stable, though there are still some thing that needed work and improvement. Hopefully they will be addressed in time for the final production miners to start shipping to people and we already got information as mentioned that things have been improved already and we are soon going to be able to remotely test not an early prototype, but a final product to confirm this by ourselves, so stay tuned for more information.