possible! ASIC USB erupter issues

[shadizzle]

Hello, Pretty new to the mining thing here...

I currently have 5 ASIC USB sticks spread across a usb 2.0 hub, and 2 units directly connected to the machine.  Having done research on these before purchase, they also have a small heatsink over the ASIC chip itself.  Backed by a 120mm server (high RPM) fan less than an inch away.  

I had gotten #5 in the mail today and went to work,  once I was done messing with the hub and connectivity issues, I am up and running.  However, I notice  I seem to catch a few HW errors than I should, and probably more importantly, one of the USB miners is accepting shares at a lower rate.  Example being :

ICA0: A:387 R:10 HW: 8
ICA1: A:385 R:5   HW: 4
ICA2: A: 80  R:4   HW: 3

etc...

According to CGminer 3.1.1, ICA2 is hashing at the targeted/advertised rate, though the accepted share is so low. Sadly, I was not paying close enough attention while mining with the four to know if this is an ongoing issue or not.  

It seems to me I am having a high number of HW errors given that such a high flow fan and added heatsinks are onboard.  Is it possible I have bad USB sticks, or is this more simple and along the lines of a USB hub being the cause?

Any help/pointers  etc is much appreciated! I can provide Screenshots or anything if needed.

Thank you


System:
AMD FX6100
Win7 64bit
990FX chipset

[astutiumRob]

Either
1. you dont understand how hashing works and the _almost_ random chance of finding one or
2. your hub is faulty / isnt supplying enough power

Shutdown, swap 0 and 2 in the hub restart, try again - is it always the 3rd one that's_much_ lower or soes the perceived performance issue "move" to AMU0 ?

[shadizzle]

Hello,

Thank you for the response..

I went ahead and swapped positioning of the USB sticks, similar configuration of 3 units on the hub, and two in the machine.  It appears to be the hub thus far, they are all within proper tolerance range of each other.  I will continue to keep my eye on it, and plan on replacing the hub in the near future.  I noticed the USB 3.0 hubs seems to work best for everyone, so I will more than likely go that route...

As for the first part, I know the general idea of hashing, however you're right, I am unfamiliar with the bitcoin process in depth, as I am still reading when I can.

Last question,

Is the main reasoning for going with a USB 3.0 hub due to power/amperage only? Or does the data I/O really tie up that much traffic?

[HashCoinProject]

I have many HW error too, an easy way to minimize that is set the difficulty to 2.
I believe it's caused by the design itself, since I'm using a pretty high-end USB hub.

[shadizzle]

Hello,

Thank you for  the response..

Could you elaborate a little? How would I reset the difficulty to a lower level?  Will this impact my overall accepted shares in a negative manor?

I am sorry for all these  ignorant questions.

[altcoinband]

Hello,

Thank you for  the response..

Could you elaborate a little? How would I reset the difficulty to a lower level?  Will this impact my overall accepted shares in a negative manor?

I am sorry for all these  ignorant questions.

Some pools allow you to choose a difficulty, like slush's pool.

[shadizzle]

I see,

Ok,  I will do a little more toying around and see if anything changes. 

Thank you for your responses everyone, though can anyone tell me the answer to the "why usb 3.0" question above before this post is closed?