Hey there jstefanop, just received my order a couple of days ago, and it seems like one of my miners has an issue where it runs normally for a brief period of time (avg 2-min hashrate of ~4.1 running at 756), and after a few minutes, it ramps down to ~2.7 or so, and that's where it stays. I have two other units that work fine, and do not exhibit this behavior. I've tried adjusting the core voltage a bit (swept the from 0.7 - 0.825), but nothing seemed to have an effect. Didn't alter mem voltage. Another note is that I don't notice this drop when I run at lower frequencies; at 684 for example, all three sticks seems to have a avg 2-min hashrate of 1.75.
Not sure if it helps, but its unit #2815. Any thoughts or suggestions? Got a multimeter in case that's useful. Thanks in advance!
I wouldnt be worried unless your average hashrate, and pool hashrate (the last two numbers) show lower than expected hash. Also try isolating that miner to see if its a hub/power issue.
Thanks for the reply. Definitely have excluded the USB ports: my two other miners seem to operate fine on the same port(s); both are very stable for long runs, one at 832mhz and the other at 796mhz. And sorry I didn't mention it originally, but yes: the average hashrate and the pool hashrate both trend downwards, once this "throttling" kicks in. Currently I'm running it at 700mhz / .75v core / 0.9v mem; for the first ten minutes, it hashed at about 3.8Mh/s, but then it throttled around that time, and the values have now settled at 2.63 / 2.68 / 2.76Mh/s after running for about 25 minutes total. That's what happens pretty much every time I run them: two run great, but this one throttles down to 2.7Mh/s, and I can't seem to get it to hash above that rate unless I restart BFGMiner.
On a side note, it sounds very similar to what soifigured described in this post:
Got some assembled and up and running. I'm noticing some are slowing down to about 2MH after running for an hour or so. Is this a self preservation feature? Are they running too hot? I hit all the small heatsinks with my pyrometer and temps are all about 60C.
Thanks again for all the help, appreciate you taking the time to help us out.
*Edit: I might have found a sweet spot for the voltages on this miner, I dropped the memory down quite a bit and currently I'm having a nice run with it at 756mhz, using core voltage of 0.73v and memory voltage of 0.79v. The values currently being reported by bfgminer are 4.25 / 4.22 / 4.29Mh/s, and it's been running for ~15 mins or so. I kept mulling over the fact that the miner was just being throttled, but still was basically healthy, for all intents and purposes. So I decided to try reducing the stock voltages a bit and see how things go. Will let you guys know if this works out for me, gonna give let it run overnight.
** Final edit: results of the overnight run are good. All three miners are working great now.
