All About BTC, LTC, ETH mining as well as other alternative crypto currencies
A few days ago we have published a version compiled for windows of the cpuminer for the 5-chip Gridseed ASICs that fixed the power consumption when using the devices for Scrypt mining only (6-8W power consumption). This version has allowed the user to set the operating frequency of the chips inside up to 900 MHz and our unit seem to work best at 850 MHz as at 900 MHz is seems to have more HW errors. That however did not stop us from modifying the cpuminer to allow for even higher operating frequencies of the Gridchip GC3355 processors, so now we release an OC Edition of the cpuminer that will allow you to go all the way up to 1200 MHz operating frequency.
The OVERCLOCK EDITION we have made allows you to go for higher operating frequency above 900 MHz – you can try running the chips at 950, 1000, 1100 and 1200 (use the –freq=xxx command line parameter to set these frequencies). We have found our test miner to perform best with 850 MHz, however yours might be able to function at higher frequency without problems (many HW errors), so you might want to try higher than 900 MHz all the way up to 1200. At 1000 MHz the device consumes about 9W and at 1200 MHz the power consumption might go as high as 10W, so there should be no problem with the cooling, however the chips might not be able to run well at so high frequencies and can give more or only HW errors.
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.
In our recently published first impressions from the Gridseed 5-chip Scrypt ASIC devices we have mentioned that with the provided cpuminer mining software the power consumption of these devices will remain high (up to 60W) even when only mining Scrypt cryptos. Normally the power consumption for scrypt mining with these devices should be about 6-8W, but it seems that the originally provided mining software had an issue. Gridseed have apparently provided an updated cpuminer, however only as a source that you needed to compile and there was no version available for Windows, so we have spent some time and efforts in order to compile the fixed version and provide you with a downloadable executable for Windows.
As you can see after starting the new fixed version of cpuminer on our 5-chip Gridseed CG3355 ASIC device we now have 8W of power consumption instead of the 56W that we previously had with the older version of the cpuminer software. So if yo are using the older version, then you should update immediately to the new one as it will significantly reduce the power usage of the device to the promised level for Scrypt mining. Note that this reduction in power usage may also help you get slightly higher overclock, though such is not guaranteed. Note that we have compiled and provide you with a downloadable version of the fixed cpuminer for Windows only, use the link below to get it.