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Ok, trying to figure out if I have a Freak of a USB Miner on my hands here or a dud.

I have a Raspberry Pi up and running using a 10 port "treefrog" powered USB 2.0 hub. (sku #HY-HB-8101)

I started out with the usual tutorial found at:
http://learn.adafruit.com/piminer-raspberry-pi-bitcoin-miner/to-stop-mining-dot-dot-dot

Is a great tutorial and gets you up and running with an old cgminer, 3.1.1.

However after a few house I noticed the Hardware errors were climbing.  After just a few minutes it showed 14%!    Figured I'd just leave it for a bit and see what happened.

The next day, after work I come home and its now showing 49% errors!  I also noticed on the LCD Plate that it showed 11.51GH/s... yes 11.51GH/s performance from 10 USB Miners that should be only doing about 334MH/s.

Screen shot evidence:
http://imageshack.com/scaled/medium/824/tmum.jpg (http://imageshack.com/photo/my-images/824/tmum.jpg/) Uploaded with ImageShack.us (http://imageshack.com)

I'm thinking that this can't be right... Or maybe it is?  Dunno

I start searching around and found a thread where someone upgraded their cgminer to a newer version and that seemed to help, so far, except that this one USB Miner is still acting odd according to cgminer.  I've seen it show as high as 50GH/s on this one device.  

As I said I finally figured out how to fire up cgminer 3.4.3 in Raspberry Pi OS but its not quite right, need it running as a background service I believe before PiMiner.py will be able to connect to it to utilize the LCD-plate.

I'm a novice to Linux based OS' and derivatives so may just not be aware of what I really should be doing to do it right.

Ultimately I would like to be using the latest cgminer in conjunction with the LCD-Plate.  Perhaps the Python code needs to be updated to work with newer cgminers?  Anyone proficient enough with python to help out?

So after I got cgminer 3.4.3 running this evening I let it run for a good 30 minutes to see if there were any hardware errors.  If I'm reading this summary right, its clean?
http://imageshack.com/scaled/medium/849/xhfq.jpg (http://imageshack.com/photo/my-images/849/xhfq.jpg/) Uploaded with ImageShack.us (http://imageshack.com)

I think that's enough for tonight, I'll leave it running over night with 3.4.3, curious how it fairs.

Cheers,

Xwolf

This is a symptom of a bad USB hub. Poor power delivery usually leads to fake hashrate or ridiculously high HW errors. My money is on if you touch that specific USB miner, it will be significantly cooler than the other USB miners that are accurate, because it isn't actually hashing.

I had the same symptom before when I used the cheap chinese 10 port hubs. Get a better hub, or directly plus the usb miner into a root port instead of a hub. It'll work fine.

Also, I recommend BFGMiner instead of CGMiner. More feature rich, and actually has accurate hashrates. I plugged in 70 USB miners to 7 10 port powered hubs and within a few hours, almost all the miners were exactly 336 mhash average.

https://dl.dropboxusercontent.com/u/9768004/70bes.png

I did consider the Hub its self and will check to see if I can find one that is better locally.

This one wasn't cheap in cost, $40 but I can easily return it, and even though it wasn't cheap in cost perhaps it is cheap in build quality.

I would really like to utilize the LCD Plate I have with my Pi I guess I'll try to contact the author of that PiMiner Python script to see if he can help.

I'll try a different HUB and report back.

Try direct plugging your USB miners to your computers root ports first. if the problem follows the usb miner, its the usb miner. if not, its the hub.

Heya, it's all about the power supply.  The adapters that come with hubs are in all honesty, complete rubbish.  Most of the "Chinese" hubs have a 1A or 2A power adapter if you are lucky.  Divide that by 0.5 and that is how many miners you can run off the hub regardless of how may more ports it has.

As an example, I purchased two of these:

http://www.ebay.com.au/itm/10-Ports-USB-2-0-HUB-High-Speed-for-PC-Laptop-Mac-/200495286945 (http://www.ebay.com.au/itm/10-Ports-USB-2-0-HUB-High-Speed-for-PC-Laptop-Mac-/200495286945)

They came with no power supply (did not bother me as I was going to use my own).

Then purchased one of these, the 50w version:

http://www.ebay.com.au/itm/AC-DC-5V-10W-15W35W-50W-100W-150W-Universal-Regulated-Switching-Power-Supply-PSU-/231044303781?pt=AU_Lighting_Fans&var&hash=item35cb504ba5&_uhb=1 (http://www.ebay.com.au/itm/AC-DC-5V-10W-15W35W-50W-100W-150W-Universal-Regulated-Switching-Power-Supply-PSU-/231044303781?pt=AU_Lighting_Fans&var&hash=item35cb504ba5&_uhb=1)

This powers, so far, 16x USB miners, 2x USB Artic Cooler fans, the Rpi itself via backfeed.

Rock solid and no issues. I have a colleague that is having random reboots which was caused by low power supply outputs.

Just my 2c.

D-Link and Rosewell make 10 port hubs with 3.5 to 4.0 amp PSU's that work well with the Pi.  When using a Pi you need a full 0.5 amps per miner or you well have problems.  I went through this with my first setup using a cheap 7 port hub, error rate and rejects up the kazoo.  Used a 3.0 amp D-Link HUB-7, it has been mining 5 sticks and a fan  with less than 0.8% error rate and 0.05% rejects.

Another problem with the Pi is no RTC, you need to set the clock on each boot or wire in a RTC daughter board.  You can find a RTC board for $6, a 3 wire install.

i too had this problem awhile ago. it was the cheap hub i was using. after many trial and errors, i found the solution. i swapped out the cheap 10 port hub i had to a belkin 7 port hub, but you have to make sure to buy a seperate power adapter to power each hub. a dc 5v-3.5amp should do it.http://http://

looks like bad hub and what the hells going on with AMU8 47GHs XD
try finding AMU8 and un plug it its the only one messing up so you hub might be a bit over what it can handle