Pending new revelations to my situation, I think my controller won't be able to handle more than one of these at a time. Sidehack said he can get 2 running at a time off a raspberry pi, so 2 Pi's should let me run my 4. I tried following the directions on the 2pac thread and couldn't do it.

Anyone with the patience to talk me through a raspberry pi setup? We can do it here to benefit everyone, a new thread if it's tangential, or by private message.

I need to know:

1) do these need drivers on a pi? How do I find and install them properly?

2) instructions I've seen discuss "building" cgminer. How do I do that?

Can you show an example of how to do that? I have to reboot my pi daily as it hangs, but I have to start by hand.

it doesn't make sense, sort of. why does one work (alone), and not the other?

looks like ill have to buy a USB hub. any recommendations? i can grab one today.

Might it be possible to run two instances and use the --usb switch to target specific devices? I haven't used the switch since initially playing around with cgminer, so I might be misrecalling the exact purpose of of it...

not looking to blacklist it (think it disables it when you do), even though I am not sure if it would keep that one at 100 while having the others go to 200+

How does run multiple instances of cgminer and set different frequencies? All my USB ASICs detect on all the instances. If I disable ASIC on the first instance, the second instance I fire up also shows the ASIC as disabled too. So, I'm not sure how you configured your setup to run different frequencies. Can you help me and provide some details?

I don´t know if it´s common here, but I use the deb package screen to login to a session via SSH. With screen you can keep the session running even if you log off. When reconnecting you can resume the session with the command screen -r. I don´t know if cgminer is able to run two instances in two different sessions. If it is you could start two instances with two frequencies.
Otherwise I would git clone cgminer in a second folder, maybe cgminer2, and compile it there. Then maybe you could start two cgminers in two sessions using screen.

 I purchased a Drok from Amazon but there are cheaper meters out there all the way down to $6US

Is it out of stock everywhere?

So I hope I didn't break the potentiometer on my 2pac. Is it the potentiometer designed to stop turning at a certain point? Or does it continuously turn? Because mine continuously turn and don't seem to stop at any place. I'm trying to figure out if I'm at the highest voltage setting. Unfortunately I don't have a volt meter, so I was hoping by turning the potentiometer far enough, it would stop at one point indicating the highest voltage. If I'm not making sense please let me know and I'll try explaining again.

Will this hub be able to power 2pac?

https://www.amazon.com/D-Link-including-Charging-Adapter-DUB-H7/dp/B0000B0DL7

The ASIC's are actually on the PCB side (I think). At least that was one of the takeaways I got from this post. As for the temp I just pointed a laser temp probe at (what I think are) the ASIC chips.

Interestingly, the silicon around the chips are considerably warmer than the chips themselves... 

Mine are at 41C on the ASIC chip itself (according to my point and shoot laser probe). So I could overclock some more? I am with ppetrovic68, what is a realistic max temp?

Also, I'm thinking of building up a 3D printed cowl to sit on top of the USB hub with a case fan pulling air through the cowl. Anyone done anything similar that I can "borrow" ideas from? I have nearly the same setup as Biodom with the Superbpag 7 port hub connected to a Raspberry Pi. I think it would cool to have two of the Superbpag hubs lined up side by side with a aero cowl leading up to a 80mm case fan.

Typo on my end. Here is the correct parameter, --usb, used like so:

I know that you are joking, but 55C is burning hot...not F
my rule for compacs/2pacs is: if i can touch the metal with a finger for a few seconds without feeling a burn, than it is OK.
...I had students getting blisters when they "tried" a 72C water bath with their fingers thinking that it is roughly at a room temp..

Hi, I have mine running at 250,   I have a Temp probe in between
the board and heatsync currently its at 54.8 Celsius  is this a good temp?
What temps should it run at?

Pull the latest code and have at it.

Nope.   

Use the -n flag and --dev flag in cgminer to select the device you want.

Use --enable-gekko to support the Compacs and 2Pacs.

Do you mean reading the voltage with a multimeter at those soldier points?

Thanks for the tip on the USB meter, got one in the mail.

Which raises an interesting question (at least to me). If I have my chips clocked at 225MHz via the command line, but I have the vcore set at 1.50 via the potentiometer, how much wattage is actually being pulled? Is it the full 10.18 as referenced in vh's OP? If that is the case then what would be the advantage of keeping the vcore at 1.50 but the clock at 225MHz? Stability? Seems it would be smarter to scale back to get as close to 8.71 vcore without causing HW errors, correct?

Thanks for the patience, I just want to make sure I understand.

That fixed the HW errors. They are now 0 after running for about 10 minutes. I also backed the throttle down to 225MHz. I have a little USB fan cooling the devices but right after I posted my first reply I got a seg fault that crashed Raspbian and had to hard reboot it ('reboot' command wouldn't actually reboot it, it would just hang). I am not sure if they are related but since I had the devices hashing all night @ 100MHz without issue it seems too coincidental to not be the cause. I'll keep an eye on it for sure.

I definitely don't have 20 year old eyes anymore but it looks like the dial on the pot has two flat sides. Are you saying I should turn it nearly half way? Clock or counter clock-wise? Is there a way to check what the actual wattage being pulled is (like in the USB management)? I didn't see it on a cursory glance but maybe its something that can be calculated?

Thanks for the support guys!

hmm... yes it is very possible I didn't finish connecting the dots there.  99.2% likely.
I'll add it shortly.