Ok so I've tested the risers idea, that didn't work (Also did it with the GPU directly in the motherboard).
FYI: All the system use team view to remotely log in and check the setups.
This has already been done
I'll try this now, however if I reapply the same OC manually (although no numbers change) GPU0 works at full speed.
All my systems are 7x or 8x GPUs - I'm not sure if the asus Z270-A will allow you to keep the onboard GPU running with that without causing another issue?
FYI: All the system use team view to remotely log in and check the setups.
It's because GPU0 is the one that also has to do the work for the display.
Go to system properties->Performance->Select "Adjust for best performance".
Remove any background photos.
Reduce the display resolution.
Close any other programs that may be using the GPU.
Go to system properties->Performance->Select "Adjust for best performance".
Remove any background photos.
Reduce the display resolution.
Close any other programs that may be using the GPU.
This has already been done
I have the same. 6x1070 setups. I did notice the the clock get limted on gpu0. I noticed that if I open chrome and leave it open it goes away
I'll try this now, however if I reapply the same OC manually (although no numbers change) GPU0 works at full speed.
try if you can use the onboard GPU for the regular video output, then all your 1070s will perform full without loss on 1st card 
if bios complains, look if you have somewhere "Windows 10" enabled, disable this and just enable Bios itself to UEFI only - thats enough for running (just during installation i'd to enable always Win10 and remove all GPU's, then disable Win10 and add all GPU's and leave the onboard GPU as primary video output)
if bios complains, look if you have somewhere "Windows 10" enabled, disable this and just enable Bios itself to UEFI only - thats enough for running (just during installation i'd to enable always Win10 and remove all GPU's, then disable Win10 and add all GPU's and leave the onboard GPU as primary video output)
All my systems are 7x or 8x GPUs - I'm not sure if the asus Z270-A will allow you to keep the onboard GPU running with that without causing another issue?