Voltmoding and Overclocking Even Higher the Gridseed 5-chip ASICs

18 Mar
2014

gridseed-asic-higher-voltage-mod

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!

gridseed-asic-higher-voltage-mod-power-usage

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.

gridseed-asic-voltmod-overclock

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…

GPU Mining Heavycoin (HVC) Booming, Price is Still High

18 Mar
2014

heavycoin-hvc-price-chart

Now, more than a day since the release of a GPU miner for AMD graphics for mining the previously announced as CPU only crypto Heavycoin (HVC) is available, surprisingly the price of the crypto is still at high levels. The release of GPU miner already made the mining of the coin with CPU pointless, and the coin is already not so easily mineable with GPUs with the network hashrate already pretty high. Mining HVC with AMD GPUs however may be worthwhile for some more time if you have some AMD Radeon cards to spare if the exchange rate does not start to drop. We still haven’t gotten a release of a HVC miner for Nvidia that uses CUDA, but the author of CudaMiner is working on such software. The interest in Heavycoin is still quite high and you should not be dismissing it so easily.

– For more information about the Heavycoin (HVC) HEFTY1 based cryptocoin…

Some More Thoughts About the MarketsCX LTC Cloud Mining Service

18 Mar
2014

markets-cx-exchange-rate

It has been about a week already since we have discovered the new Markets CX LTC cloud mining service and have started testing it. We have decided to give it a try as it was new and interesting, so we have invested 5 Litecoins to purchase about 120 KHS worth of cloud mining hashrate at a price of 0.0410 LTC per KHS. Initially we’ve had some concerns about the service that is claiming to be using Gridseed ASIC devices to provide so attractive prices for cloud mining hashrate as compared to other services that are still using GPUs. You can check our first impressions from the MarketsCX Litecoin cloud mining service and see some of the concerns and issues that some readers that have decided to try it out as well have reported.

The good news is that a week later and the service is still here and works and today we’ve got an official reply in the comments section of the article with our initial impressions seemingly from the Support of the service. This is the reason why we’ve decided to give some updates on our experience with the Markets CX service so far and below is a quote of the post regarding some of the issues reported in the comments above:

Guys, indeed there were some technical problems a few days ago. Some user accounts with dots and uppercase characters in their E-mail addresses were affected. We have successfully solved this problem. No LTC, KHS or mining profits were lost.

It is nice that they are keeping an eye on what other people are talking about their service and taking the time to respond to users with issues that are not posted on their website, though their onsite support seems a bit slow in responding apparently. Up until today we’ve had no issues with the service so far, and today was a bit of a delay when we have requested an LTC withdraw – we did not receive a confirmation email shortly after requesting the withdraw (previously we got it in less than a minute). So we’ve sent a support ticket about the problem and have requested multiple times a withdraw to test if we are going to receive an email. A bit more than an hour later we got a confirmation email and the withdraw was completed, so we’ve closed the ticket (we got no answer, but maybe the issues was addressed). So a few more hours later we’ve requested another withdraw to see if the problem with the delay still exists. Again we did not get a confirmation email within a few minutes, but requesting the withdraw again and we got the confirm email in a moment (again just one with two requests made).

Another thing that we did not like much about the service is the rapid decline in price per KHS, we have purchased hashrate just a week ago at 0.0410 LTC per KHS and back then this was very reasonable price and now the price is 0.02442 LTC per KHS. We are not sure if this is because of users that are dumping their hashrate or by the service pushing new hashrate at a lower price, but we are not very happy that in just a week time our hashrate lost almost half of its value (a common problem with cloud hashrate services with trading exchanges). Currently there are more than 34 MHS worth of hashrate available on the exchange, so at the moment you can buy some cheap LTC mining hashrate. We do recommend caution though as this is still a new service and we still do have some concerns, so not a good idea to invest a lot of Litecoins in it for the moment. If you are interested in checking it out you can get with a few LTCs like we did, as it is probably not a good idea to invest in thousands of KHS for the moment!

– For more information about the Markets CX Litecoin cloud mining service and to try it out…

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