Bitcoin Forum

Hello i've recently bought this hub (Sipolar 20 Port usb2-0 hub)

http://i00.i.aliimg.com/wsphoto/v3/979153532_3/Sipolar-20-port-USB2-0-HUB-USB-HUB-Industrial-grade-HUB.jpg

I have connected it to a raspberry pi. Although when i plug in my 4 bitfury twin usb devices it, it operates for 2 minutes
and then the devices are turned to zombies in the cgminer.


Have you encountered any similar issues? Is it a matter of power drainage? Is it because of Raspberry pi?

Thanks!



The bitfury twin is this

http://www.eyeboot.com/image/cache/data/Product%20Pictures/twinfury/Photo%2026-3-14%201%2036%2055%20pm-800x800.jpg

It could be the hub is not giving the thumbs enough power. Currently I have 20 Gridseeds (2 x 10 port hubs) and a blade plugged into a 7 port Dlink hub. They are all happily working off of 1 USB port on my pi.

I have used a d-link h4 and then the hub but the same results. Although it seems that it works on a windows version of cgminer.

Forget about pi
It is sharing Usb irq with Ethernet. for USB mining and have I/o in general pi is pain in the ass due to hardware design

You using the same version of cgminer on the pi and windows? Did you compile cgminer yourself on the pi?

What alternative could i use ?

BFGminer would work.

Beaglebone I guess or Linux  pc

I have tried the same version both on windows an rpi yes.

Is Beaglebone relieved from these kind of issues?

I will got one shortly and let you know. But from hardware point of view USB is completely independent from Ethernet  ;)
Ps i am refereeing to bb black

there's an old USB HUB thread with reviews on all kinds of hubs.  you should search the forums to find it.

this particular hub sucks.

I'm now trying again on windows with the latest ver of cgminer and will let you know!

The hub works well for about 20 minutes with cgminer 4.3.0 in Windows.

Now i will try to compile the latest version of cgminer on minepeon and run it from there!

Any details on the power supply driving the hub? My recollection is that you should
plan on a minimum of 1A @5V for each BiFury when running at it's normal low clock
speed. I think it can go as high as 1.8A.

A few other debugging thoughts:

- How long will it run with just 1 BiFury plugged in?

- How long with two?

- How long with three?

If shrinking the number of BiFurie's makes things better, think power for the hub.

That hub puts out only 0.5A per port.
You should be getting half speed @ 2ghs, imo.
You can't use the hub. Something like orico would work wonders.
Or you could buy eyeboot's hubs they work great up to 49 TFs.

Did you already set " dwc_otg.speed=1 " ?
http://www.raspberrypi.org/forums/viewtopic.php?f=28&t=53832

It seems that i will run for much longer with less number of devices.

I think this hub it is defective by design and cannot provide more power to each of the usb than
0.5Amp.
The power supply which is used is 12V DC, 5A. Shall i try it with a stronger power supply?


I may give it a try with dwc_otg.speed=1.

Now i am encountering the following issue.

The raspberry pi hangs and the mining stops after one hour of operation.

Do you have any oppinion regarding this?

Is the  dwc_otg.speed=1 the solution to this problem?

If it runs longer with fewer miners then it is almost certainly a hub power problem. 12V*5A = 60W = 3W/port = 600mA/port MAX (assuming 100% efficient power conversion). So it seems that the hub is designed to only deliver 500mA/port.

I doubt a bigger 12V power supply will work as the 12V - 5V conversion in the hub is going to be the limiting factor.

It runs for 24hours with 4 miners without interruption.
If i add 2 more miners raspberry pi freezes after 30~40 minutes of operation.

Yeah I would suggest a couple of these bad boys:

http://www.eyeboot.com/10-port-usb-hub

It can deliver close to 2 amps on 5 of the ports

Those are and have been the best choice but shipping cost was always steep.

This thread is over a year old...

Yes but still relevant. :D

There was a deal on Amazon before for $35 usd with free shipping but unfortunately to USA only. Its finished at the moment but might be back later...