.... All looks good. Few freezes and eventually system starts. Card gets recongnized after few mins, done DDU, reinstalled GPU drivers. Problem is then I'm mining even desktop lags a lot and mining performance is like 10 times slower on all cards.
This is weird, if it
freezes sometimes, there's really a problem.
But seeing that the your rig starts, this might be a power issue, not your PSU but maybe from the
riser, it wasn't
powered.
The MoBo's PCI-e slots are powered which is used by the GPU, those 8-pins power connectors are the
supplementary power.
You can't use the cards properly with incomplete power source, it could be the riser, it doesn't supply the power from the PCI-e slot.
Could Windows reinstall help? Maybe it has to be installed while that pci-e card connected? I'm out of ideas.
Not at all, you can plug anything without needing to reinstall Windows..
It doesn't look like a software issue to me.
Well it is powered. Because if I don't connect that SATA power cable GPU doesn't even light up. And it hits all the performance not even that GPU. Other 2 gpus are directly to pci-e x16. Also if i put them all to pci-e sockets everything is fine, just the heat issue on middle one, so that's not psu power issue. I still got room left. Using evga g2 850. It takes off the wall only 600w then all gpus in pcie x16 sockets. Maybe someone could recommend some kind of Linux distro (graphical interface, Havnt used it for 5 years so I have forgotten even basic commands, will have to Google it) so I could boot it off usb flash drive and try how mining speed is down there?