Posts Tagged ‘Scrypt ASIC


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.


Yesterday we have received our order of a single 5-chip Gridseed DualMiner device that is capable of Scrypt mining with a hasrate of 300 KHS as per the deice description, so we have already played with it for a bit and are ready to share what are our first impressions. A few days ago we have also shared our First Impressions from the DualMiner USB Scrypt ASIC that uses a single Gridchip GC3355 processor. The single chip device did work pretty well and although it needs a bit more improvement on the software side, it is well designed and works well in terms of hardware. So we were eager to try out the more powerful 5-chip version that we actually don’t know how to call exactly yet – Gridseed Golden Orb, Gridseed 5-chip Dual Miner, Lightningasic DualMiner it goes by all of these names with some variations in the color of the cooler – gold, silver, or red. The hardware inside remains the same however, capable of mining BTC and LTC at the same time or only Scrypt cryptos such as LTC with a higher performance then when working in dual mining mode. We don’t care about the BTC mining capabilities of the device, so we are going to focus only on the LTC (Scrypt) mining capabilities and performance.


From the outside the miner looks pretty good, so we have opened it to see what is the build quality inside the device – checking the components and the cooling design. Unfortunately we cannot say that we are happy from what we saw inside. While the PCB design is good and seems well made, the additional components on top and the wiring disappoint. We see masking tape used to insulate components like for example the USB to COM board, amateurish solution for the button next to the adapter power socket etc. Furthermore our unit had two of the wires from the USB to COM board squashed by the bottom part of the cooler over one of the Gridseed chips. This could cause issues with cooling and can also create problems with communication between the device and the computer feeding it with work, so we had to fix some of the wiring and insulation in order to avoid possible problems in the future. We can say however that we do not really like the build quality for something that is currently sold quite expensive, it seems amateurish and like it has been assembled in someone’s garage without adequate quality control. We really expected more, especially after seeing how good the single chip USB miner was made…


After fixing the hardware inside the miner it was time to fire up the device and try it out. So we had to look for some instructions how to use it as well as drivers and mining software (no documentation or software was included). We actually had some trouble having the miner properly recognized on half of the computers we have tried – the drivers did not function properly or did not assign a COM port for the device – it is connected via a USB port. Then to our surprise we’ve had to use a modified version of cpuminer that will work with the device and that software is really lacking advanced features that are found in the likes of cgminer for example. The miner software even does not give you a local report on the actual hashrate of the device, it only shows 0 KH/S, so you have to rely on the hashrate reported by the pool. There is also no adequate information about stale shares or hardware errors, so on the software miner side there is much work to be done for proper user experience – we need at least a recent version of cgminer modified to support the ASIC device.


Moving to the power consumption of the 5-chip Scrypt ASIC miner. By specifications the device should consume about 8W for Scrypt only mining and 60W for Scrypt and SHA-256 (LTC and BTC) combined mode. We are only interested by the Scrypt mining functionality of the device, so we expected to see very low power consumption, but to our surprise the watt meter showed 56W. It seems that even though we are not mining BTC with the miner that functionality is still active and the miner consumer power as if the device is working in both BTC and LTC mining mode. We’ve read that there is apparently an update released to fix the power consumption issue, but only released as a source code for the miner and you need to be able to compile it yourself – hardly anything that most miners are able to do by themselves.

So to conclude our initial impressions. It seems that these 5-chip Gridseed Dual Miners are far from ready for release to end users, however the company (companies) making them have rushed them on the market due to the user demand. They do not seem well enough built with good quality control, the mining software is in a very basic form just to say it is available and works. There is no detailed documentation for setup and use, so you will have to figure some things by yourself… not to mention any support, so if you have a problem you will have to rely on the mining community for help. It seems that these 5-chip Gridseed ASIC devices are not even in Beta, they are more like an Alfa stage product rushed to the market. We suppose that Gridseed did not even consider using these as a separate units, but had in mind to sell them in packs of 10 or 20 orbs with an additional controller that they will be connected and controlled from. We’ve ordered a single unit just to try it out before deciding is it is worth go for a 10 (3 MHS) or 20 unit (6 MHS) solution, but after reading about issues people are having with these and having issues ourselves with the single orb devices we can say that we are not happy with what we got for our money. We expected much more and actually a finished product, not some half baked solution that you can hope will work somehow and not cause you issues. We cannot recommend to an average user or miner these devices at all, if you are a technical guy with a lot of experience and knowledge in mining and miners (including software) you might like the challenge however. The single chip DualMiner USB ASICs however are a much more finished and user friendly product, so you might want to check these out for now and stay away from the bigger 5-chip devices until they become a more complete and properly working solutions.


This week we have finally received a DualMiner USB Scrypt ASIC based on a single Gridchip GC3355 processor that is capable of mining both BTC and LTC or only LTC (SHA-256 and Scrypt), so we can share some of our first impressions already using the device for a day. The device uses a dip switch to switch between the mode active at the moment (LTC and BTC and LTC Only) and there are two virtual COM ports available – one for BTC or other SHA-256 and one for LTC or other Scrypt crypto mining (you need to install a virtual USB to COM driver from here). When you are in BTC and LTC mining mode you are supposed to get about 500 MH/s for SHA-256 (BTC) along with about 40 KH/s for Scrypt (LTC), however we are and you are also probably going to be more interested in the performance of the LTC (Scrypt) mining mode only as this way the ASIC uses less power and provides more performance and you better go with 70 KH/s LTC instead of 40 KH/s LTC and 500 MH/s BTC nowadays. One important thing is that when the device is in LTC mode only you need to use the BTC COM port (the first one) and when operating in Dual mode the first COM is for BTC and the second for LTC.


DualMiner USB Scrypt ASIC uses a modified version of cgminer that comes along with an extra GUI that might be more appearing to the new to mining users, however we prefer to use directly the cgminer from the console (version 3.1.1). The extra parameters you are passing to the cgminer include “–lo” for the LTC only mode (Scrypt only), “-S //./COM12” to set the COM port used by the device and “–dualminer-pll 850” to set the operating frequency of the chip. When you switch to LTC mode only the ASIC increases the voltage to 1.2V and uses 850 MHz to achieve 70 KH/s, in BTC & LTC mode apparently the voltage is 0.9V and the clock frequency is 550 MHz for 500 MH/s and 40 KH/s respectively. You can try increasing the MHz value a bit to about 900 to squeeze a bit more performance, though you should be careful as not all devices apparently can work at that frequency and you better have some sort of extra cooling.


Our tests show that when the device is used in a pool, the reported hashrate is a bit above 70 KH/s, the screenshot is from ScryptGuild with difficulty set to 16. You need to set the difficulty for the worker lower in order to get good actual performance due to the not so high hashrate of these miners. For the first 24 hours our DualMiner USB Scrypt ASIC has managed to get away with just about 0.15% HW errors running at 850 MHz with an extra fan for better cooling, s things are looking pretty good. We are going to perform some more tests and publish them here in the next few days, so stay tuned for more information abut these USB ASICs based on Gridseed’s GC3355 chips. And while we like how things are working with this low power Scrypt ASIC, we are not going to recommend the purchase of single units due to the low hashrate that each device provides and if you are going to invest in more of these USB ASICs, then you might want to check out the 5-chip Gridseed miners supposed to offer 300 MH/s per devices – these will cost you less for the same total performance. For the moment the price at which the DualMiner USB ASICs are being sold they are not that attractive choice, and we have ordered one just to play around with it. We are waiting for one of the larger 5-chip units to arrive in the next few days, so we are going to be reviewing it as well soon.