Posts Tagged ‘Gridseed more overclock


Yesterday we have reported about a solution for volt modding and overclocking even higher the 5-chip Gridseed ASIC miners for use with the cgminer software modified to support Gridseed ASICs. We have tested the voltage modification on our older and newer revision ASIC miners, and t has allowed us to go from 850 to 950 MHz overclock on the newer miner. Unfortunately it was not working on the older ASIC miner and it was not working with other software miners such as bfgminer or cpuminer for Gridseed. Meanwhile there is an update that solves both of these issues we’ve experienced with the earlier solution. In fact you only need to solder a bridge between another two points on the ASIC miner – note the second green strip on the right from the firs one from yesterday where you need to solder too. This modification will permanently activate the higher voltage and should allow you to overclock all (most likely) Gridseed 5-chip ASICS regardless of their revision and firmware version with all of the available software miners that support them.


The power consumption after applying the permanent voltmod is 10W per 5-chip Gridseec ASIC miner with the fan or about 8W if you remove the fan and use passive cooling (not recommended for voltmoded miners) or use another form of active cooling. Doing the permanently activated voltmod solution we are still able to get best results at 950 MHz with no to very few HW errors and performance of a little over 400 KHS. Pushing for 1000 and 1050 MHz is also possible (going for 1100 MHz or more results in only getting HW errors), but the number of HW errors increases as well, so the actual performance might be lower than running the miner at lower frequency such as 950 MHz with less HW errors. As always do try on your own hardware as there is a variance and you might be able to get better results with your miners. If you do plan to do the hardware voltage modification be aware that there is a risk of damaging the ASIC, especially if you are not good with the soldering iron, so proceed with caution.


It seems that the community has figured out a way to do a voltage mod for the Gridseed 5-chip ASICs that allows for higher overclock frequencies and thus even higher hashrate. We have decided to try out the mod ourselves and report our own findings and results with our older and newer dual mining mode ASIC devices from Gridseed. What you need to do in terms of hardware modification to your miner is to solder a bridge on the place marked with the green line on the photo above. Then you need to run the latest version of the modified cgminer for Gridseed with an extra option for the gridseed options line “voltage=1”. Note that the space where you need to solder a bridge is very small, it is designed for SMD resistors and if you are not experienced with a soldering iron you will have trouble performing this modification by yourself. Also if you are not very careful you may damage the device by soldering something that should not be soldered and thus shorting the ASIC, so be very careful should you decide to mod the device or higher voltage!


After performing the hardware modification to our two miners that are from different revisions apparently we have tried running them with the modified cgminer (download link for the windows binary below, for the source). The older revision of the device we’ve got with CP2102 USB to UART Bridge Controller trying to run the setting to set the higher voltage from within cgminer returns an error about the firmware not supported. The device has a firmware version 01140116 and apparently this version is not supported, even modifying the cgminer to recognize it as supported firmware did not help in being able to overvolt and overclock the miner. The other newer ASIC device with STM32 Virtual COM port driver was with the correct firmware version 01140113 and the miner apparently did activate the overclock and overvolt mode. The power consumption of the device we have measure with the voltmod and running at 950 MHz frequency was with about 2W higher than at 850 without the voltmod, or with other words 8W instead of 6W (in fanless mode) with 2W more with the fan working (10W and 8W respectively). If you are doing the voltmod however we would not recommend to use the device in passive fanless cooling mode, though at 850 MHz and with no voltmod we have been running a single miner for already 48 hours without any issues.


With the increased voltage of the Gridchip GC3355 processors we were able to get from 850 MHz with no or very few HW errors (361 KHS) to 950 MHz with no to very little HW errors (404 KHS) after the modification. We could also go to about 425 KHS at 1000 MHz with very few HW errors, going up to 1050 MHz produces almost 450 KHS, however the number of HW errors we are getting at that frequency is significant, so the real performance is probably much lower than at lower clock speeds. What we would recommend as the most stable result is to go to 950 MHz as overclock frequency as good starting point after doing the voltmod and go up in 50 MHz steps to see how will your miners perform at higher frequencies and if they will do any better results. The latest version of cgminer supports overclock up to 1300 MHz in 50 MHz steps, so you can go pretty high, though you should be careful as the increased voltage and frequency might lead to damage of the device.

You can download cgminer 3.7.2 for Scrypt mining on Gridseed 5-chip GC3355 ASICs on Windows OS here…