Erputers getting 7.7% HW error rate on Raspberry Pi and cgminer

[c789]

I have 2 Erupters in a "Pluggable" powered hub on the 512 version of RPi running cgminer 3.1.1 on Raspberian. I have a fan pointed at the setup and no parts get over 55c temperature. It's been running for a little over 24 hours and I'm getting lots of HW errors (7.7%) with the following message:

Code:

ICA0: invalid nonce - HW error

Is there anything I can do to correct this?

cgminer.conf

Code:

{
"pools" : [
	{
		"url" : "PoolAddress:Port",
		"user" : "UserName.WorkerName",
		"pass" : "Password"
	}
]
,
   "api-listen" : true,
   "api-port" : "4028",
   "expiry" : "120",
   "failover-only" : true,
   "log" : "5",
   "no-pool-disable" : true,
   "queue" : "2",
   "scan-time" : "60",
   "worktime" : true,
   "shares" : "0",
   "kernel-path" : "/usr/local/bin",
   "api-allow" : "0/0",
   "icarus-options" : "115200:1:1",
   "icarus-timing" : "3.0=100"
}

Command to run

Code:

cgminer --config /home/pi/cgminer-3.1.1/cgminer.conf -S /dev/ttyUSB0 -S /dev/ttyUSB1

[c789]

Update: I stopped running on the pi and moved to a PC running Xubuntu. After 18 hours the HW error rate was the same as on the pi, so the pi is not what's causing the errors.

At this point I suspect it's due to poor quality control on hastily-made Erupters, or my input settings are incorrect. I hope it's the latter because that can be fixed. Any suggestions?

I moved everything back to the pi...it's saving me at least 100 watts over the PC

[yxt]

How much power can your ps provide?
plug one unit direct into your PC and post your cgminer output after some time

[c789]

The hub provides 3A power (500mA to each) and I'm running 2 Erupters on it with no other devices.

I plugged one of the Erupters directly into my PC and ran it for around 12 hours but I still keep getting the HW errors, around 8%:

Code:

ICA0: invalid nonce - HW error

[poohbah]

I see 1.0% - 1.5% errors on my erupters with a rosewill 330 USB hub and cgminer 3.3.1. I used zadig to install the usb driver on win7.

It's closer to 1.5% with 4-5 erupters, and closer to 1.0% with 1-2 erupters. My guess is that it's your USB hub or maybe the older cgminer version.