All About BTC, LTC, ETH mining as well as other alternative crypto currencies
Sandor111 has released an updated version of his cpuminer fork adding a TUI (Text User Interface) containing the most important information that you would need to know for your Gridseed ASIC miners in an easy to read format (source here). Another new useful feature in the latest release is the autodetection of the number of chips, so no need to set it manually via the command line anymore. We have a windows binary available for you, and we do recommend to give it a try if you were sticking to cgminer because of the TUI available there, especially now that cpuminer also has one. If you want you can still download the previous cpuminer for Gridseed with no TUI, we’ll have it available for people that prefer to use that, and below you can download the new TUI version for windows.
Gridseed ASIC users will be happy to learn that there is a new fork of the cpuminer software with support for Gridseed ASIC miners (for Scrypt only mining) thanks sandor111 over at the Bitcointalk forum. He has added support for local hashrate reporting which was one of the key missing features of the previous builds, but he did not stop at that, he has also added support for per chip frequency autotuning (automatic overclock until the best frequency is reached for each chip) and the ability to manually set frequency for each miner by using a single instance for multiple devices. There is also support for the new Gridseed G-Blade miner, you only need to set the number of chips to 40 for each of the PCBs of the Blade Miner in order for the local hashrate to be properly reported.
We have compiled a windows binary of the new miner and you can find the source here. Great work and essentially what the original cpuminer should’ve been from the start, and now it is finally here, simple and easy with all the right features available. We are currently testing the new miner, especially the autotune feature, so far it seems to work quite well, but be aware that it could take some time for the miner to adjust frequencies, so make sure you set a starting frequency that is closer to what you expect that the device should be capable of. For example 850 MHz for default non modified 5-chip ASIC, 950 MHz or 1150 MHz if you have dome some sort of a voltmod already. Do check the included Readme file for a description of the options and some examples as well as for a simple, but effective Batch script for using backup pools with the miner. If you find some problem or an issue using the miner please do report it, so that it can be addressed.
The last time we talked about voltmodding the 5-chip Gridseed ASIC devices we did what we considered the optimal voltmod for optimal performance/power consumption. Back then we discussed what could be the theoretical maximum you might be able to push the voltmod to in order to try to get the best possible overclock, though that would be achieved with an unreasonably high power usage. Well, we have decided to try out and push things to the maximum, namely replacing the R52 resistor with a 68 kOhm 402 1% SMD resistor. With this modification we were aiming to get 1400 MHz while still fitting in the power consumption that the ASIC could handle in Dual Mining mode or about 60W, however running in Scrypt only mode. With these settings we were planning to get stable around 600 KHS if we would succeed in actually running the GC3355 chips at a bit over 2 volts.
So we’ve replaced the R52 with a 68 kOhm resistor, assembled everything up (do not try to run the ASIC disassembled with this mod as you can burn the voltage regulators in a matter of a few seconds). Firing up the ASIC has shown a total power usage of about 58-61W, so pretty much what we have planned initially, however the problem was that the Gridseed device did not want to function properly at that voltage after the modification. It simply did not send any shares back to the server, neither it was showing any HW errors, through apparently the device was working and communicating with the miner software. so we do not recommend to push things so much trying to get the maximum performance regardless of the power usage, better stay at at the reasonable recommendation by using a 47 kOHm resistor which should get you close to 500 KHS at about 20W, running the miners stable at about 1150-1163 MHz. Even if we were able to get the device working properly with the 68 kOhm resistor mod and with 60W power usage it wouldn’t be reasonable to get just about 100 KHS more with an extra 40W of power. You could of course try resistors with values in between 47 and 68 kOhm to see where the maximum would be, but for us it is not reasonable to get just a few more extra KHS with double or triple the power used. Still feel free to experiment and report your finding and as usual be very careful not to burn your hardware while experimenting with it. If you go with more than 47 kOhm resistor be extra careful if running the device with the bottom of the cooler not attached as you can easily burn the voltage regulators of the ASIC!