If you're on Linux, you can use this command:

There's no need for something so complicated. This will work just fine:

Is there any way to tell which Gridseed is not running at maximum speed using Sandor's cpuminer? For example, in this screenshot:

http://i.imgur.com/piH2iDA.png

Gridseed #1 is running really slowly, which probably means that I need to either re-seat the heatsink or resolder the resistor. However, how do I determine which one is Gridseed #1? When I unplug the USB cable to a Gridseed, the UI doesn't update to let me know that it's dead, and every Gridseed looks like it's still hashing.

You really need to cut it out with the personal attacks. It's obvious to anyone who's been following this thread that you have some sort of personal vendetta against Zig for introducing an alternative mod. It doesn't matter if you've 'invented' the original mod, nobody likes an asshole and you're doling it out in droves.

And I've had the clicking issue as well, and I've only done the R52 mod. The only time I heard it though was when I plugged in the power to the USB hub, but not the 12V power. It went away after I turned on the 12V power. I thought it was kind of weird, but didn't think much of it at the time, and it never happened again except for that one time. All my Gridseeds are hashing away fine too, so I'm not sure what I did to cause it to click.

Only a few hardware errors. The autotune takes care of optimizing the clock speed.

I'm running 20 Gridseeds off a Raspberry Pi and did the 49.9k mod and 5V fan mod to each of them. When I use bfgminer with a clock speed of 1200 MHz, even though the app reports that I'm hashing around 10 MH/s, my pool only reports about 5.5 MH/s.

When I use sandor's cpuminer with autotune on and at 1200 MHz, the results are better. My pool reports 8.5 MH/s, but this isn't quite up to 10 MH/s. I'd expect my hashrate to be in the mid 9 MH/s range; my rejected share percentage is only around 1-3%.

Tomorrow I'm gonna try running two Raspberry Pi's with 10 Gridseeds each to see if the combined speed is higher than running one Raspberry Pi with 20 Gridseeds, but does anybody have any ideas on how I can increase the hashrate to match what I expect? I have 80 Gridseeds in all, and if I'm losing 1.5 MH/s on 20 Gridseeds, that's 6 MH/s across all 80. That's equivalent to buying another 16 unmodified Gridseeds, which is not an insignificant amount.

--freq=850 is the setting the clock speed for all the Gridseeds.
--gc3355-freq=/dev/ttyACM0:900 is setting the clock speed for a specific Gridseed. If you have multiple, you can set them like so: =/dev/ttyACM0:900,/dev/ttyACM1:850,/dev/ttyACM2:950

You can use either. I don't know what'll happen if you use both though, presumably the --gc3355-freq is more specific and will override whatever is set on --freq. If this is the case, you can set a default clock speed for all the Gridseeds and override a few that need to be set differently.

I did the 49.9k resistor mod, but I'm having an issue:

http://i.imgur.com/fXkhIQq.png

For some reason, although the Gridseeds are running at 7.65 Mh/s collectively, I"m only getting around 3.6 Mh/s effective. It's like this no matter what pool I use. Is this normal, and if not, any idea on how I can fix it?

I've done the voltage mod with 49.9kohm resistors and the 5V fan mod on 8 of my Gridseeds, but I'm having a problem. I'm using the Hashra image with a Raspberry Pi, but the Gridseeds are only stable up to 950 MHz. What's weird is, they run perfectly fine at 950 MHz, but the moment I try bumping it up to 1000 MHz, they basically fail to hash at all. To give an idea, at 950 MHz, my pool reports ~3.5 MH/s with about a 3-5% reject rate. At 1000 MHz, my pool reports ~0.01 MH/s with a 80-90% reject rate. Any idea what could be causing the problem?

Yes, for the Molex connectors, the yellow is 12V, the red is 5V, and the blacks are the grounds. I would recommend that you stick to Molex connectors because you can easily buy or find the male connectors and solder them to barrel connectors to make them removable. You can buy 8-to-1 barrel splitters on eBay, cut the end off, and solder it to a Molex connector.

I've finally figured out the source of the problem. It was the power adapters! I purchased 4 of the 20-Gridseed bundles, so I received 10 power adapters (each one can power 8 Gridseeds). After pulling my hair out for weeks, I finally narrowed the problem down to the power adapters. Only 2 of the 10 I received were working properly when powering multiple Gridseeds. When I cracked them open, it became really obvious as to why:

http://i.imgur.com/TKh1lyr.jpg

http://i.imgur.com/LfOVqlI.jpg

Look at those capacitors bulging! All 10 of them had bulging capacitors. The capacitors in the 2 power adapters that were working had the least amount of bulge, but they were bulging as well. The worst ones were even leaking, and one even had a capacitor that was loose and barely connected!

If you're using one of these power adapters and are having issues where your Gridseed miners look like they're hashing, but are not submitting shares after a few hours, you can run this simple test to see if the power adapter is at fault:

Plug the barrel connector of the power adapter directly into a Gridseed and listen to the fan noise. It should be a fairly audible whir. Next, plug the 8-to-1 barrel splitter into the power adapter, then plug one of the barrel connectors on the splitter into the Gridseed. Listen to the fan noise again. If it sounds the same, your power adapter is working properly. If it sounds like it's spinning slower, then you have a bad power adapter.

I've since switched all my Gridseeds to use an ATX power supply and now they're happily hashing away.

Raspberry Pi here, as well as a regular desktop. Gonna try the regular desktop again and see how many I can get running this time.

When you say "not mining", do you mean that it's hashing, but not submitting any shares? That's the same issue I'm getting, but my limit seems to be around 7-9 Gridseeds.

I've tried 4 different USB hubs and it looks like the max number of Gridseeds I can get running at the same time is around 7-9. This is using the Raspberry Pi across 3 different distros (Hashra, Scripta, Zoomhash). The hubs were:

4-port USB hub - 5V @ 1 A adapter, all 4 Gridseeds working
10-port USB hub - 5V @ 1 A adapter, 8 Gridseeds working
10-port USB hub - 5V @ 2.5A adapter, 8 Gridseeds working in Scripta, 9 Gridseeds working in Hashra.
Monoprice 24-port USB hub - 5V @ 4A adapter, 7 Gridseeds working in Scripta.

So I don't think it's related to the power.

This is the Monoprice 24-port USB hub. I don't have it in front of me right now, but I think the power adapter for it is 12V at 4A = 48W. The Gridseeds are powered using 12V at 7A = 84W power bricks. Each one powers 8 Gridseeds each, and the Gridseeds run in scrypt only mode. I purchased the 20x Gridseed kit from Zoomhash, 4 of them.

I've run it for several days now, the screenshot was just an example. I normally use cpuminer because cgminer crashes after a few hours and disconnects all the Gridseeds, and I have to reboot the Raspberry Pi in order to get them all back.

I should be getting around 28 MH/s for 80 Gridseeds, but my pool only reports 6.5 MH/s. Strangely, one of the Raspberry Pi's has only 8 miners connected to it and each one is submitting shares, unlike the remaining 3 Raspberry Pi's that are hooked up to 24 miners each and only 1-3 Gridseeds per Pi are submitting shares. I'm not sure if it's because of the USB hub or the number of Gridseeds used, but this is the kit from Zoomhash so I'm under the assumption (perhaps erroneously) that everything should work.

I'm trying to get 80 Gridseeds working across 4 Raspberry Pi's (24 Gridseeds for each Raspberry Pi using Monoprice 24-port USB hubs). However, I'm running into an issue with btbartle's cgminer:

http://i.imgur.com/wbdUUuA.png

It looks like the Gridseeds are hashing, but only 3 of them have submitted shares, and a very low amount at that (and strangely, it always increments by a power of 2). Does anybody have any idea why this is happening? I've tried using the default 600 MHz speed and also using cpuminer, but the results are always the same.