Archive for the ‘Mining Hardware’ Category


When we’ve made our previous guide for dual mining BTC and LTC on a Gridseed 5-chip GC3355 ASIC we’ve only had an earlier revision of the miner that used CP2102 USB to UART Bridge Controller. Now that we already have a newer revision with the STMicroelectronics Virtual COM Port we have decided to update the guide with information on how to Dualmine on these ASIC devices. Note that we do not recommend using these devices for dual mining mode, but for Scrypt only mode instead, but you are free to decide for yourself. The advantages of using Scrypt only mode are the low power consumption and heat, the ability to overclock higher, including with a voltage modification and a choice of multiple more up to date software miners. Note that the only way for the moment to use the Dual Mining mode on the Gridseed 5-chip GC3355 ASIC devices is to use the special version of cgminer 3.8.5 for BTC mining (SHA-256) along with the special modified version of cpuminer for Gridseed for LTC mining. Due to the way that the Dual Mining mode is realized on these ASICs using a more recent version of cgminer or bfgminer for LTC (Scrypt) mining on these devices along with the cgminer for BTC mining is not possible at the moment.


– Open up Windows Device Manager and go to the Ports (COM & LPT) and note the COM port that is written behind the STMicroelectronics Virtual COM Port driver
– Download and run the latest version of Zadig
– From the Zadig interface select Options and choose List All Devices
– From the Dropdown list of devices select STM32 Virtual COM Port and click on Replace Driver with the WinUSB driver selected
– Download the dualmining package that we have prepared for windows that contains cgminer 3.8.5 for BTC mining and cpuminer for LTC mining
– Edit the BAT files for the two software miners included in the archive with your settings for BTC and LTC mining pools
– In the LTC-START.bat file you will see an option “gc3355=\\.\COM4”, here you need to change the COM port number to the one you have seen in the device manager before updating the driver with Zadig to use WinUSB
– First you need to start cgminer 3.8.5 for BTC mining, wait a few seconds until the software starts up and connects to the pool and starts working
– Then start the cpuminer for LTC mining, note that you will need to wait for some more time here before the miner connects and starts working, but it it takes more than a minute maybe something is not right

If you still haven’t used cpuminer for Gridseed you should know that the software does not report local hashrate, so the zeroes you see are normal, it is actually working and sending shares. Also note that when in Dual Mining mode you will not be able to overclock the device as high as when only in Scrypt mining mode, so it is normal to be getting lower hasrate. As we’ve already said, we do not recommend the Dual Mining mode and suggest to use these ASIC devices for Scrypt mining mode only, especially if you want to run multiple devices.

Download the DualMining package for BTC/LTC mining on Gridseed 5-chip GC3355 ASIC for Windows…


KnCMiner has just announced their first Litecoin mining ASIC device already available for pre-order with a Q2/Q3 shipping date, 100 MHS minimum Scrypt mining hashrate and a price of $9995 USD (without VAT). Not much information is available for the moment, but trusting KnCMiner is much safer than Alpha Technology who have not yet released a product on the market, unlike KnC who have some history and good feedback from users that have purchased Bitcoin ASIC devices from them. Note that Alpha Technology has also announced target for shipping for Q2/Q3 this year, but their Scrypt ASIC devices are rated at up to 25 MHS and you will need to pay £5450 UK pounds (without VAT) for that. So if you haven’t pre-ordered a Viper Scrypt miner from Alpha Technology then it is much more reasonable to go for the 100 MHS KnCMiner Titan Scrypt ASIC. Meanwhile Gridseed remains the only company currently making Scrypt-capable ASIC devices and shipping them on the market, so that is the only option you have for the moment for an LTC ASIC device. It is also interesting to note that current customers queuing for a Neptune SHA-256 ASIC are able to exchange their queue if they are more interested in the newly announced Titan Scrypt ASIC miner.

For a bit more information about the upcoming KnCMiner 100 MHS Titan Litecoin Mining ASIC…


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.