USB erupter troubleshooting; slow hash rate

[aznatama]

So I have been hashing for about a week on my setup, maintaining speeds of 333.3~334.0 MH/s, <1.3% error rate using bfgminer 3.1.3 on win7.

Today, after restarting the mining (switched to mining ASC last night, moving back to BTC now), the speeds are slower.  ??  I didn't see the speeds right before restarting the bfgminer, but the current stats after 2 hrs of mining are an average between 303~312 MH/s with a very high HW error rate of 6.6~6.8%.

I've tries power cycling all the hubs, reconnecting USB rebooting computer, no change.  Could the included power adapter have degraded within one week of operation??  I ahve a 5v 40a regulated psu on the way, but this issue is very odd since it's been stable for over a week already.

Here's the setup:
2x Rosewill RUH-500 w/ 8 eruptors - 5v 4a power
3x 10-port ebay hubs w/ 2 erupters - 5v 2a power
1x erupter run via USB extension from front panel USB (only device on this "hub" which is connected to mobo.

I tested the voltage at the USB ports, and all the random ports I've tested read between 5.0~5.1v.  There's 2 USB fans cooling the eruptors, as well as a room fan which I have directed at the setup after I encountered this issue.  Chips are definitely cooler now w/ all this airflow, but no change in hashing rate.

Any suggestions???  I'm missing almost 1gh of speed!

[kabopar]

Suggest that you try bfgminer 3.2.1, I had significantly lower HW errors after moving from 3.1.4 to 3.2.0 then 3.2.1.  It may not fully solve your problem, but will help.  Also check if any of your power adapters is running either very hot or cooler than normal (if one died, the others will try to compensate, but will be overloaded).  If one of them is 'cool'  (I would suspect the 2A ebay ones), then measure its output voltage (disconnect the power plug, use a voltage meter to measure between the inner contact and the outer sleeve), if you don't read 5V, then it is 'dead'.  You can replace this with a suitable power adapter from your local electronics store or on-line.  You may find that you can run more Eruptors with a higher capacity power adapter.

Good luck

[aznatama]

The weird this is that I have been using the same version of bfgminer the entire time.

I measured all the power, and it's at 5v.  I also measured power while it was mining, and it also showed 5v.  Nothing wrong with the voltage.  bfgminer starts up just fine, with everything running at 333mh/s, but after a bit of time, it will drop.  I tried unplugging some of the erupters, but that didn't solve anything.

Also, the one erupter that's plugged directly into my computer used to work at 333, but has the same issue now as well.

I'll try the newer version of bfgminer now.

Tried BFGminer 3.2.1, still slower than expected.

This is really weird and baffling.  Worked fine first week, now it's slow. Tried new erupters that I haven't plugged in yet, and same thing.  

If it matters, the code I'm using is:

Code:

C:\bfgminer-3.2.1-win64\bfgminer.exe -o pool.50btc.com:8332 -u ******** -p ****** -G -S all --icarus-options 115200:1:1 --icarus-timing 3.0=100

[Zeek_W]

I had the opposite one day. An Erupter was reporting > 800 MH/s solid for about 20 minutes (according to minepeon). Was a scary time wondering if it was in a final burst before death.

[kabopar]

has anything else change?  ambient temp?  are the Eruptors running hotter than before?

(your bfgminer settings seem to be normal)

[kabopar]

Does the lower hash rate and higher HW error apply to all BE's or only to some?
I had a case where 3 of my BE's developed a much higher HW error rate and had lower hash rate than others.  I disabled them, removed them, allowed them to cool down then inserted them into free ports on another hub, and this 'cured' them.
To disable specific BE: with Bfgminer in focus, type 'm', then select the one that you want to disable with the arrow keys, then type 'd', wait until its LED lights up constantly, then you can remove it.
(by the way, if you used "-S erupters:all" in your command line/short cut, instead of "-'S all", you would get the option 'I' to identify the units, but some people claim that this reduces the hash rate).

Good luck

[HellDiverUK]

As poster above says, try -S erupter:all - the old Icarus options are depreciated, and not necessarily optimal.

[ssateneth]

Change

Code:

-S all --icarus-options 115200:1:1 --icarus-timing 3.0=100

to

Code:

-S erupter:all

[aznatama]

I took out one erupter from each hub (5) and let it run for a few hours:

With 3.2.1, the hw errors were lower, but no change in the low hash rate.

However, I decided to plug them back in anyways and use the erupter:all option as suggested above, and now they all seem to be working fine the past 30 min, all hashing at 333-335MH/s.

I'll see how they hold up when I get home tonight.  Hope they're fixed.  Thanks all.

[madcratebuilder]

In my case using the usb hub at maximum power, ie 8 miners in a 4 amp hub I get poor results.  Remove 1 miner so I have .5 amp head room and am back at 336-337Hps per asic miner, and >1% HW error rate. YMMV.

[kuusj98]

So maybe you ruined the USB port?
Try another or try another pc and see if that helps.

[ppafford]

I have a RasPI running minepeon 0.2.5 and 0.2.4 ( tested both ), a DLINK USB Hub ( http://www.amazon.com/dp/B00008VFAF/?tag=stackoverfl08-20 ) and a Red Fury USB ASIC Bitcoin Miner 2.2-2.7GH/Sec By BITFURY with the BFGMiner

When I start up MP I get the 2.2-2.7GH/s after a few minutes it drops to 250MH/s and a little longer down to 10 or below MH/s

Why?