Posts Tagged ‘Scrypt ASIC

gridseed-5-chip-asic-new-version

In our article about our first impressions from the Gridseed 5-chip Scrypt Asic earlier this month we were not very happy with our initial experience from the device. It seems we’ve got one of the earlier builds that were not very well built and the software for using them was also at a very early stage. Today however things look much better, we just got a new unit that we have ordered and it is much better built and uses the STM32 Virtual COM port driver instead of the CP2102 USB to UART Bridge Controller that our previous unit had.

cgminer-gridseed-stm32

We have tested the new ASIC device and it works just fine with the STM32 drivers installed with the modified for low power usage cpuminer for Scrypt mining by giving the virtual COM port number of the device. The ASIC also worked just fine when we have replaced the STM32 vitual cOM Port driver with WinUSB using Zadig to use cgminer 3.7.2 for Scrypt mining on the ASIC. We still haven’t tried using the new 5-chip Gridseed ASIC device to work in dual mining mode with TLC and BTC mining running at the same time as apparently the dual mining method that have already described for our older ASIC using the CP2102 USB to UART Bridge Controller is not working for devices with STM32 Virtual COM port drivers, so we’ll be getting back with more details on that later on when we figure it out.

For the moment however we are much more satisfied with the newer revisions of the 5-chip Gridseed LTC/BTC ASIC devices, especially when we take into account the improvement of the software support side for them in the last few days.

gridseed-dualmining-on-windows-success

The 5-chip Gridseed GC3355-based ASIC devices that support Dual Mining for Bitcoin and Litecoin are not that easy to be used in the Dual Mode, because you need to have two different software miners running at the same time. There is a bit of specifics in what and how you need to do in order to mine both BTC and LTC at the same time and after a bit of tinkering we have managed to finally make things work as they should under Windows. You need to download a special modified version of cpuminer for Scrypt (LTC) mining and a modified version of cgminer for SHA-256 (BTC) mining. We have compiled the two software miners and you will find the download links below. You will also need the Zadig software in order to replace the virtual USB to COM driver with WinUSB driver for the cgminer to detect and work with the BTC mining side of the ASICs.

zadig-gridseed-dualminer-usb-config

– 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 CP2102 USB to UART Bridge Controller and click on Replace Driver with the WinUSB driver selected
– If you have multiple 5-chip GC3355 DualMiner USB devices connected you may need to repeat the procedure for all of them
– Download, edit and run the BTC.bat file from the modified cgminer 3.8.5 for the Gridseed ASICs to start the miner working on BTC
– Download, edit and run LTC_ONLY.bat file from the modified cpuminer for Gridseed ASICs to start mining for LTC (check what your COM port is and edit it). You need to add the parameter “dual” (without the quotes and two dashes in front) to the command line in order for the Dual mode mining to start working

It seems that there are some ASIC devices that may be using different virtual USB to COM drivers other than the CP2102 that our unit has (for example ST32 Virtual COM Port), unfortunately we don’t have any of those to test with. You can however try to make things work by replacing the other driver with WinUSB, just select the right name from the dropdown box (do not try to rename drivers, it is pointless) and Replace it with WinUSB (you may need to unplug and plug the USB cable to the miner after that). If after installing the WinUSB driver over the virtual USB to COM driver the ASIC does not work with cgminer, you just need to uninstall the driver from the Device Manager and unplug/plug the USB cable to the device for it to install the original USB to COM driver and it should be functioning again with cpuminer (note that this way you may have it running on a new COM port).

This is it, you should have the miner running both SHA-256 (BTC) and Scrypt (LTC) mining withe the two software miners and the total power consumption should be about 60W. Note that you may need to lower the operating frequencies a bit for when mining the Dual BTC/LTC mode as the chips get hotter. If you want to mine only BTC you can stick only with running the modified cgminer, for LTC only you need the modified cpuminer without the dual option in the command line. The most attractive aspect of the Gridseed 5-chip GC3355 ASIC however remains their very low power consumption for Scrypt mining only mode, so think again if you really wan to run them in the Dual Mining more or for BTC only and not in LTC only mining mode instead.

gridseed-5-chip-scrypt-asic-performance

Yesterday in our first impressions from the Gridseed 5-chip Scrypt ASIC device we have shared that the modified version of the cpuminer software is not reporting local hashrate. This is a problem as you can hardly know what is your current hashrate, especially when you start overclocking the device to get some extra performance out of it. You need to rely on information reported by the pool about your worker’s current hashrate, but these tend to often report lower or inaccurate results than actual hasrate. This is due to the fact that pools base the reported hashrate on the submitted shares for a given period of time, so result can vary. We can report that the average hasrate we are getting from our 5-chip Gridseed DualMiner ASIC device in terms of Scrypt mining performance to be hovering around 300 KHS with the stock frequency of 600 MHz that the five Gridschip GC3355 chips inside run at.

We could get the chips to run at about 850 MHz, but they were giving out quite a few HW errors, at least visually as the cpuminer software does not report actual number of stale shares or HW errors that the device makes. Seeing a lot of the red error messages means you are probably getting a lot of HW errors and should try reducing the clock frequency with 50 MHz or more. With 800 MHz the device was running more stable with much less HW errors, however this result was achieved with the use of the standard cpuminer software supplied with the device. Apparently this version of cpuminer had a bug and did not disable the BTC core and as a result mining Scrypt only you can get up to about 60W power consumption. By using the newer fixed cpuminer for Gridseed the power usage got down to the 8-9W range and we could overclock the device at 850 MHz with more stable results and very few HW errors. With 850MHz clock we got pools to report hashrate going up to about 400 KHS which is definitely a nice improvement though the newer version of the cpuminer still does not report local hashrate, so it is hard to get more realistic rate for the performance of the device when overclocked.

If you wan to overclock the Gridseed ASIC devices you need to use one fo the preset frequency values as they will not accept just about any frequency that you send to them. The lst of accepted frequencies consists of the following values: 250, 400, 450, 500, 550, 600 (default), 650, 700, 750, 800, 850 and 900 MHz. It is possible that with the version of cpuminer linked above that ensures low power consumption the ASIC devices may be ale to run pretty stable even at 900 MHz, however we still haven’t extensively tested that. Still even when using 850 MHz with about 400 KHS does not sound bad at all as compared to the claimed stock 300 KHS at 600 MHz.


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