Quote from: Subw on July 07, 2017, 03:13:31 PM

Quote from: Vann on July 07, 2017, 02:42:55 PM

Quote from: Subw on July 07, 2017, 02:36:40 PM

Quote from: Vann on July 07, 2017, 02:28:25 PM

the problem is not the amount of current, it's mixing grounds from multiple sources

actually grounds from multiple sources SHOULD be connected to have the same potential among power sources.

powering USB risers from secondary PSU is OK and works on my farm

I would bet BBT has built more rigs than most here. I would take his advice and that of a PSU manufacturer that you should never mix power connections to the motherboard, which is exactly what's happening when you power a riser with another PSU that's not connected to the motherboard.

you were told already, when using USB risers you do not send any power to motherboard, dunno what it is so hard for you to comprehend...

btw that BBT idiot claimed sgminer in linux do not have RX hashrate drop, guess what? it have...

I comprehend that you don't understand USB risers are not electrically isolated from the motherboard and share a 3.3V AND ground connection to the motherboard. You also don't understand what BBT said and is doing. He reached out to AMD and others to see if an issue that affects most miners can be addressed. What BBT claimed and showed was that when he reached out to AMD to discuss the issue about the Polaris line and the Claymore epoch benchmarks figures showing a significant hash drop in future epoch's, in response he received a confirmation from a senior manager at AMD that large professional miners were using SGminer in Linux with OpenCL 2.0 and DO NOT have the same issue, which is what he reported and showed. He also asked the community to verify those claims to make sure they were correct. After receiving feedback from members here and others stating SGMiner seems to be affected as well, he has reached out to AMD again asking for clarification to their original statement. Once he receives a response, he will let everyone know.

https://www.youtube.com/watch?v=l3XOtQtFKSQ&feature=youtu.be&t=978

https://youtu.be/ZzAbECBnJmY?t=4031

https://www.youtube.com/watch?v=PXoPFPqU3Y8&feature=youtu.be&t=4822

I for one, applaud BBT for looking out for us and hopefully getting this issue resolved as I'm sure many others do as well.