Quote from: AltScope on April 16, 2018, 04:05:38 PM

Quote from: klintay on April 16, 2018, 02:01:54 PM

Quote from: AltScope on April 16, 2018, 01:54:32 PM

Quote from: jarvisparvis on April 16, 2018, 01:01:22 PM

These helped me.
If you dont want to invest in a higher powered usb hub.

For each miner undervolt all memory voltage to as low as you can before they stop hashing. To do each individually i have small usb hub i use to test each one at a time, easier access to measure the voltages with a dmm/dvm/voltmeter too. I think the default (see start of this section)is 0.8v upper limit is 9v (over this = damage).

I was suprised to find some of my moonlanders still hashing at .675v so i used that so bettween .675 and 0.7 was my range. The lower the voltage the less heat and draw from the psu. depending on your psu/amps.. if your running 11 miners check the warmth of your psu. You probably find it feels quite warm to hot, so no doubt this could be causing some malfunction in the psu power output. Try running less miners say 5 for an hour and see if the psu is cooler.

Then you need to set the core voltage. 0.725 v is the best for clock rate at 756mhz (stable no errors and a better mining rates over time than 796mhz with errors)

However if you do wanna run them at 796mhz -832mhz ive found .750 v core good. But the idea is to reduce the strain on your usb hub psu so .725 v probably the best bet.

Now the last tip if you still get errors is keep your psu cool. My psu is a black plastic block type. I attach a piece of thermal silicon pad (covering entire psu base surface) then mount on a piece approx 5inch long rectangular aluminium tube (most diy retailers have an aluminium fittings and strips section). Seems to keep the psu cool.

Most usb psu's for retail usb hubs are fairly cheap-to- produce plastic cased so they dont go to town with cooling...but the tip works.

Nice tips. My hubs PSU is pretty hot but I'm not noticing errors, might put a fan near it to cool it down. I need to get a better one really, nothing against the chinese but their included PSU's can be a bit dodgy

which usb hub are you using? what is the voltage of the psu?

https://www.alibaba.com/product-detail/High-speed-10-Port-USB2-0_60620365527.html?spm=a2700.details.maylikever.6.141e1e36TYjQnu

its a 12v 10a psu, runs 10 at 756/768 pretty well.
I found some ok looking industrial cctv transformers the other day (12v 15A) that were tempting as it would give me a few more amps to run the pi with 12v usb charger and the 2 fans I've mounted for cooling

That 12V, 10A PSU should give you plenty of power, 120watts. That's 2.4 amps per port. I would not use an old cctv transformer its output will not be as clean as a switching power supply. The bad part is that hub has 5 DC to DC step down converters in it, one for every two ports and they are only rated for 5 amps or less each so even with a bigger external power supply you may overheat the Dc to Dc converters inside if you try to pump too much current thru the USB ports.