New cpuminer Fork for Gridseed ASICs with Hashrate Reporting and Other Useful Features

22 Apr


Gridseed ASIC users will be happy to learn that there is a new fork of the cpuminer software with support for Gridseed ASIC miners (for Scrypt only mining) thanks sandor111 over at the Bitcointalk forum. He has added support for local hashrate reporting which was one of the key missing features of the previous builds, but he did not stop at that, he has also added support for per chip frequency autotuning (automatic overclock until the best frequency is reached for each chip) and the ability to manually set frequency for each miner by using a single instance for multiple devices. There is also support for the new Gridseed G-Blade miner, you only need to set the number of chips to 40 for each of the PCBs of the Blade Miner in order for the local hashrate to be properly reported.

We have compiled a windows binary of the new miner and you can find the source here. Great work and essentially what the original cpuminer should’ve been from the start, and now it is finally here, simple and easy with all the right features available. We are currently testing the new miner, especially the autotune feature, so far it seems to work quite well, but be aware that it could take some time for the miner to adjust frequencies, so make sure you set a starting frequency that is closer to what you expect that the device should be capable of. For example 850 MHz for default non modified 5-chip ASIC, 950 MHz or 1150 MHz if you have dome some sort of a voltmod already. Do check the included Readme file for a description of the options and some examples as well as for a simple, but effective Batch script for using backup pools with the miner. If you find some problem or an issue using the miner please do report it, so that it can be addressed.

You can download the sandor111 fork of cpuminer for the 5-chip GC3355 ASICs for Windows OS here…

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59 Responses to New cpuminer Fork for Gridseed ASICs with Hashrate Reporting and Other Useful Features


April 23rd, 2014 at 00:07

This would not detect my gridseeds.

The readme doesn’t make reference to this switch in the sample bat file:


Do I need to change/repeat that to correlate to my gridseed STM32 virtual COM ports? I couln’t see a number assigned to them.



April 23rd, 2014 at 00:16

OK whoops I found the reference. This is my BAT file now:

minerd.exe –freq=850 –gc3355-autotune –gc3355=DEV0,DEV1 –gc3355-chips=5 –url=stratum+tcp:// –userpass=Xxxxx.x:xxxxx

..but still it cannot find the gridseeds, whereas cgminer has no problem.


April 23rd, 2014 at 01:26

For the line “–gc3355=DEV0,DEV1” I tried replacing DEV0 and DEV1 with various COMx numbers, STM32, and the individual serials of each gridseed, to no avail.

A previous post about setting up gridseed says that the COM port numbers disappear once you install WinUSB drivers. I tried removing the STM32 com ports in device manager to see if the COM number would reappear next time I plugged in the devices, but no COM number shows. :(


April 23rd, 2014 at 01:56

Reinstall the STM drivers Rowan. You have to use the STM drivers.


April 23rd, 2014 at 01:57

& thanks admin for putting this together.


April 23rd, 2014 at 02:04

I’m pretty sure the STM drivers are installed OK already because cgminer has no problem, its just cpuminer that can’t see the gridseeds.


April 23rd, 2014 at 02:19

I reinstalled the STM devices but still no luck.

Even when I uninstall the STM32 com ports from device manager, ticking “delete driver software” too), AND uninstalled the STM drivers from Add/Remove Programs, they still get re-recognised as STM32 virtual COM ports, with no COM number, when I replug the USB.


April 23rd, 2014 at 03:29

to Rowan
manually check the proper driver from list in devices (i think it’s will be two drivers)

why my gridseeds sometimes become very hot, when i mining scrypt in single mode??? (after voltmoding 1,57v @1075Mhz)


April 23rd, 2014 at 03:57

Rowan – you might have disabled the device in Device Manager. Make sure it is enabled. Also, in Device Manager right click on the device and (from memory) it’s properties and then advanced to change the com port number.


April 23rd, 2014 at 04:01

After you reinstall the STM driver you need to unplug and plug your gridseeds back in.

You can see if they are working properly in windows by going to the start button and in the search search for device manager.

Run that and look under ports drop down. If your gridseeds are plugged into a usb port on your computer somehow, (including hubs) then they will each have a com port.

Also with unistalling WinUSB and trying to re-install you may have to clean up the STM drivers then re-install


April 23rd, 2014 at 06:11

Looks great. I have 4 gridseeds. Will I be able to use this with all 4 or will I need to run an instance of CPUMiner for each gridseed?


April 23rd, 2014 at 06:45

All in one instance cpuminer: minerd.exe –gc3355=\\.\COMxx,\\.\COMyy,\\.\COMzz


April 23rd, 2014 at 15:00

Hi, how write config to start 2 Grids at on PC? Thx


April 23rd, 2014 at 18:26

Thanks for suggestions but still not working.


April 23rd, 2014 at 19:40

I think you will need this:

By the way, anyone experienced that the CPUMiner stop sending shares in a random manner that you’re forced to re-start the instance? It’s really annoying me and I can’t find any solution. However seems I don’t have such problem using cgminer. Any suggestions?



April 23rd, 2014 at 19:51

Just wondering if this is safe to run on a fanless gridseed. I used the autotune feature and was pushing one of the chips to a frequency of 975. Will the gridseed get too hot? Thanks!


April 23rd, 2014 at 20:26

It’s safe because the voltage is what causes heat, not frequency.


April 23rd, 2014 at 22:07

Stanley thats the driver I have already been using. Its getting rid of it that seems to be my problem.. after uninstalling it is still there so I can’t see my com port numbers before I reinstall it.


April 23rd, 2014 at 22:24

tHere seem to have surfaced a new minerd.exe at -> Downloads
Anyone know the difference?


April 23rd, 2014 at 22:38

I’ve been running my miners with this new version of cpuminer and so far am getting much better results than BFGMiner (CGMiner keeps crashing on me at random times). Great work sandor111!!


April 23rd, 2014 at 23:07

We have updated the package with a binary compiled from the latest source, it has some tweaks and fixes, just redownload the package above to get the latest version compiled for Windows.


April 24th, 2014 at 03:02

I have a single unit 5chip gridseed and using Windows 64. When opening the miner.exe this shows up:

What causes this?


April 24th, 2014 at 05:08


Thanks for the driver link, just what I needed.


April 24th, 2014 at 06:46

anyone know if this fork will work on raspberry pi? I just got mine, intending on using is strictly for my gridseeds, but this new fork of CPUminer is running so well on my old windows machine I almost hate to stop it.


April 24th, 2014 at 12:11

@JS , there is a download link for Raspberry Pie


April 24th, 2014 at 21:38

Thas Yuna. Anyone know how to get this running on a Raspberry Pi? I just got mine and have little linux experience.


April 24th, 2014 at 22:28

I tested the autotune out overnight on a fanless gridseed unit. It was so warm in the morning you could barely touch it so becareful running the autotune on a fanless unit.


April 24th, 2014 at 23:06

JS, the best way is to use one of the already available RPi images with Gridseed support and just add the new cpuminer in there, than to start from zero. You can check out some of these here:


April 24th, 2014 at 23:29

Thanks Admin for your reply. Unfortunately I don’t have a pi I have mine connected to my pc.


April 24th, 2014 at 23:42

MinerXD, sorry that was a reply for JS, not you. Did you see what was the frequency of the chips of the device in the morning and if it was still running fine?


April 25th, 2014 at 00:01

It was pushing them to 1024mhz


April 25th, 2014 at 00:03

The unit seemed to be running fine I was just concerned it was going to damage the chips. My gridseed is not voltmodded.


April 25th, 2014 at 06:34

Appreciate the response admin. I assumed that the RPi with gridseed support already had their own built-in miner that couldn’t be modified (other than pools). I’ll give Scrypta and Hashra Controlla a go tomorrow. Regardless of what I do I’ll be using this new CPUminer as I’m getting much better hash rates than any other miner I’ve tried.


April 25th, 2014 at 12:20

Antivirus was blocking the minerd.exe. Thanks for this! My hash rates on the mining pool look better than before while using CGMiner.


April 25th, 2014 at 16:30

I love this CPUminer… with 10 miners it gives me 300 more khash/s than CGMiner on my pool. :-{}


April 25th, 2014 at 21:33

I sorted out the COM port problem. Details @


April 25th, 2014 at 23:59

Support for individual chip frequency is added. It’s possible to run regular USB miners and G-Blades on one instance, the number of chips is auto detected.


April 26th, 2014 at 02:50

@ sandor111

Why is the kh/s averaging around 150 on CPUMiner when it should be around 360kh/s?

Which file is for the Individual Chip Frequency on the github site?


April 26th, 2014 at 17:39

The windows binary has been updated to the latest source, just redownload it and check the Readme for the new features.


April 26th, 2014 at 20:56


I’m having the same issue with this version of CPUMiner – did you find a fix?


April 27th, 2014 at 08:24

@ NellyWhads

Still having issues with the hash report difference. There was a brief moment (about 20 seconds) while mining with CPUMiner Forked of 320kh/s reprted on a pool. After that, those numbers never showed again.
All 3 of the following miner programs were tested: *CPUMiner Forked *CPUMiner basic *CGMiner
Ran a speed test and the upload speed is at 5.50Mbps from the internet provider. Ethernet connection here is ironically worse than WiFi. Ethernet mining would never get past 130kh/s. With that, I believe the issues are somewhere else.


April 28th, 2014 at 05:30

CGMiner incorrectly reports hashrate.
As many requested, a TUI has been added. You can download the Windows/Rpi binary from my git if you don’t want to wait.


April 29th, 2014 at 19:16

Anyone get this going on Scripta or Hashra Controla yet?


May 3rd, 2014 at 07:07

I”m running 20 gridseeds and everything is working fine except I can’t get gsd 10 and gsd 15 to start. They register 0 – any ideas?


May 3rd, 2014 at 10:56

MotoBean, restarting the miner software and plugging their power and usb connectors off and on does not help?


May 3rd, 2014 at 20:00

took a new look this morning and realized it was an error in the script – thanks.


May 6th, 2014 at 14:39

Running 9d
Last gridseed blade half on all 5 rigs shows zero activity
Ideas? Are we higher than 9d now?


May 6th, 2014 at 14:53

restarted all miners and last blade half now working
Is this normal?


May 6th, 2014 at 17:06

Bladex, yes there is a new version 0.9e with fixes for the G-Blade, available here:


May 13th, 2014 at 11:07

Hey, can someone give me a working template for WeMineLTC? I’m having trouble with Hashfaster, or at least I think it’s an issue on their end. I can’t seem to configure it for WeMineLTC, as it keeps saying something like “stratum connection failed” or something like that.

Email me at, and it would be great if you have your user and whatever in there, as it would help me configure it correctly. Hey, I could only mine for you, right?

Thanks to anyone who can help me!


May 19th, 2014 at 12:59

Same problem on a linux 12.04 .(running minerd as root) :
./minerd –gc3355-detect -o stratum+tcp:// -u 1AmZ3 …..

No GC3355 devices specified, please use –gc3355-detect for auto-detection, or manually specify with –gc3355=DEV0,DEV1,…,DEVn

I have a blade and a mini. and the work fine with cgminer .


May 19th, 2014 at 14:47

Add on to my previous post .

If you used cgminer, just before to start cpuminer, you must restart the computer to free the usb device .
Even if you stopped cgminer , it’s not enough .

May 28th, 2014 at 15:40

Sandor, i really appreciate all the hard work you have done updating this. its so much better than having to run an instance per gridseed.

i wonder, does this new version support Dual mining mode? i didnt see the –dual flag in the readme or the help.

Thanks again!


May 28th, 2014 at 16:52

guardLK, this is miner for Scrypt only mode, does not support Dual mining mode.


June 8th, 2014 at 14:52

can you give me an example batch file if I wanted to set my gridseed to mine at 850mhz on chip 0, 875 mhz on chip 1 and 2, and 900 mhz on chip 3 and 4.. ? autotune gets it there eventually but it’d be nice to just start it that way..


June 8th, 2014 at 23:46

Mike, you need to add a parameter like this to the command line: --gc3355-freq=5A72558F3125:850:0,5A72558F3125:825:1,5A72558F3125:850:2,5A72558F3125:850:3,5A72558F3125:850:4

You can either use the serial number of the device or the port it is attached (the ports are different depending on the OS – Linux or Windows), the example above is with the serial, then setting the frequency in MHz and then giving the number of each chip. This is for a 5-chip ASIC, for 80-chip G-Blade the line will be much longer going from 0 to 79, instead of from 0 to 4.

Mike W.

June 9th, 2014 at 03:26

so instead of –gc3355-freq=5A72558F3125:850:0 to start chip 0 at 850.. I could type –gc3355-freq=\\.\COM3:850:0,\\.\COM3:825:1 … ?

Mike W.

June 9th, 2014 at 04:29

Got it working, thanks alot! been trying to figure that out for 2 days.. lol.. –gc3355-freq=\\.\COM3:850:0,\\.\COM3:875:1,\\.\COM3:850:2,\\.\COM3:875:3,\\.\COM3:850:4

Jeff Sparkes

June 12th, 2014 at 03:55

Has anybody seen problems with getting results from a gc3355? This software properly detects my gridseed and sends it a block to work on, but seems to run into problems resetting after the block is complete. It’s a voltmodded unit, but I’ve tried with clocks from 600-1200. It was tested at 1200 by the person who did the mod, but hasn’t worked since I received it. Is it possibly from shipping damage? Google can’t find anybody complaining about this particular error message. Here’s the output from a run on Ubuntu 14.04. It also fails on Win 8.1 on another computer so that eliminates a few variables. I modified the source it prints out how many bytes write returned, -1 in this case. I’d appreciate any advice on how to debug this.

[2014-06-11 20:51:33.7354] Starting Stratum on stratum+tcp://
[2014-06-11 20:51:33.7358] 0: GC3355 chip mining thread started, in SINGLE mode
[2014-06-11 20:51:33.7358] 0: Open device /dev/ttyACM0
[2014-06-11 20:51:34.8748] 0: Resetting GC3355 chips
[2014-06-11 20:51:35.0724] 0: Failed reading firmware version
[2014-06-11 20:51:35.0725] 0: Firmware version: 0xffffffff
[2014-06-11 20:51:35.0725] 0: Unknown GC3355 Miner detected (chips=5)
[2014-06-11 20:51:35.0827] 0: Set GC3355 core frequency to 1100Mhz
[2014-06-11 20:51:39.3182] Failed to get Stratum session id
[2014-06-11 20:51:39.3183] Stratum difficulty set to 128
[2014-06-11 20:51:39.3511] Stratum detected new block
[2014-06-11 20:51:39.3511] New Job_id: 661 Diff: 128 Work_id: f99b5bbd
[2014-06-11 20:51:39.3555] 0: Resetting GC3355 chips
[2014-06-11 20:51:39.4560] 0: Dispatching new work to GC3355 cores (0xf99b5bbd)
[2014-06-11 20:51:47.6841] Stratum detected new block
[2014-06-11 20:51:47.6841] New Job_id: f421 Diff: 128 Work_id: f9a37082
[2014-06-11 20:51:47.6842] 0: Resetting GC3355 chips
[2014-06-11 20:51:47.6852] New Job_id: f4af Diff: 128 Work_id: f9a37082
[2014-06-11 20:51:47.6943] 0: UART write error 8 -1 actual
[2014-06-11 20:51:47.6943] 0: Terminating GC3355 chip mining thread
^C[2014-06-11 20:51:50.9488] SIGINT received, exiting

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