Topic: 2 x Bitmain Antminer U3 not running the same speeds? (Read 3469 times)

USB 2 hub using two kind of chip. Single Transaction Translator(STT) and Multiple Transaction Translator (MTT). In the past i had many problem while using STT usb hub.
It's hard to know which kind of chip the vendor use because almost all of vendor didn't publish this. But some vendor willing to answer the question via email.

bfgminer doesnt seem to find them at all. native support from cgminer 4.8+

Have you tried to run them with bfgminer???

Having similar issues. What do you mean with the last statement? MTT chip? i bought an icybox IB-ac611, didnt really solve anything.
Lots of people having issues with the U3 stability and performance by the way

Using powered usb hub is not a bad idea. Just find the one that using MTT chip.

Yea I have 2. I opened one and cleaned all the paste very preciclsy and with proper tools.

It seems to have fixed the problem. But now the other one also runs fine.

So its wierd. Still trying to work out.

Some people say to use a powered USB since the U3 might use a bit more and cause reset on the USB port and force a "crash" on the driver.

Maybe, but since you said it can run 6 hdd, then we can pass the psu.
The other culprit maybe overheat. Some already open the heatsink & report that the work around the chip is a mess.

Does it really matter? Its not a cheap Chinese thing for sure. I used it to run a server for a while with 6HDD's I know its capable of powering the units. But maybe I am just being ignorant?

What make would you recommend and why?

I mean what brand & type?

computer power supply 450watt

What kind of psu did you use?

I find that I have to quite cgminer, turn off the power to the U3, physically unplug the USB's from U3, turn on power, plug in USB and start cgminer, then I got another 16-24 hours of mining before it goes ZOMBIE

Nope, My timer switch doesnt work to well. Once a U3 ZOMBIES out, I gotta go into my secret lab and pull the USB cables, power down, power up, and plug the USB back in.

It just does this the whole time. Even sometimes if it does not ZOMBIE. I just restart cgminer it will do this.



 [2015-01-02 17:27:10] AU3 0 attempted reset got err:(0) LIBUSB_SUCCESS
 [2015-01-02 17:27:11] Accepted 06aad484 Diff 38/16 AU3 0 pool 0
 [2015-01-02 17:27:13] Accepted 0f623523 Diff 17/16 AU3 0 pool 0
 [2015-01-02 17:27:15] Accepted 023141f2 Diff 117/16 AU3 0 pool 0
 [2015-01-02 17:27:15] AMU 0 GetResults usb read err:(-4) LIBUSB_ERROR_NO_DEVICE
 [2015-01-02 17:27:15] AMU 0: Comms error (rerr=-4 amt=0)
 [2015-01-02 17:27:15] FAIL: USB get_lock not found (5:102)
 [2015-01-02 17:27:15] AU3 0 GetResults usb read err:(-1) LIBUSB_ERROR_IO
 [2015-01-02 17:27:15] Icarus detect (5:102) failed to initialise (incorrect device?)
 [2015-01-02 17:27:15] AU3 0 attempted reset got err:(0) LIBUSB_SUCCESS
 [2015-01-02 17:27:15] Accepted 0bed6b94 Diff 21/16 AU3 0 pool 0

Hi,
Sorry
did not have time over holiday to compile cgminer API.

I just got a new one and replaced it. Now both of them run pretty stable at 60ghs 237.5mhz@780mv.

Still, they go ZOMBIE every other day for no reason. I even used a timer plug to power down 4 times a day for 15 minutes to try and solve the ZOMBIE issues. Usually all I have to do is power down the units for 5 seconds power up and they start running in cgminer again. But I think if I do this too many times without restarting cgminer it just goes mental and everything crashes. So I got to stop cgminer, power down, start cgminer, power up, and it works again.

https://i.imgur.com/wMXLdgy.png

This would answer a lot of questions with quite a few of us having problems with this U3. It would explain why we can't get anything above ~43Gh/s.

Probably dead chip

I am not sure if this can work but you can check it by running command under cgminer folder:

You need to compile cgminer-api first:

I think its a duff.

I have been searching for hours and nobody else has anything similar to this. since cgminer 4.8.0+ it should just work with all the fine tuning handled in the background.

I hooked up a dedicated PC PSU and set it to 250mhz/800mv and the first one I got is sat stable at 62ghs and this second one, it will not budge.

Between various setting its stuck at 45ghs and wont go more.. get a new one and see what happens, return this one

I bought 1 U3 miner and got it running with cgminer 4.8.0 on Ubuntu. I had some serious issues getting it going, for some reason the supplied USB did not work and as soon as I used another it went up and I overclocked a bit. Got a nice stable 59.9 Gh/s at 780mV/238Mhz - using the stock PSU and I heard it can melt if you go over 790mV.  Whatever, i am happy with ~60Gh/s

I ordered a seconds one after selling my old stuff. Again, USB cable problem, kept on going zombie and didnt detect it properly for a while.

I unplugged the first one I got, powered down the machine, used that USB cable, powered up with the new one Solo with OC settings. It detected fine but its only running at 45Gh/s

I plugged in the first one with another USB cable I had, hotplug detect, jumped straight in and went to 60Gh/s.

Ok, so I removed the OC setting and run cgminer again then it started up fine, detecting both units. But now the new unit runs at 30Gh/s and the 1st unit at 40Gh/s.

Wierd? I turned on OC again and tried various USB ports and a few other USB cables. This new, 2nd unit just wont go over 45Gh/s - Is it normal for such a large deviation in hashing?

My pool reports 112Gh/s but cgminer says 104Gh/s - but I know no to trust the pool stats. I was hopping to get just about 120gh/s with these 2 boys.

Does anybody know why this could be happening with the new, 2nd unit I bought?

https://i.imgur.com/kwq6bIS.jpg