Wohoo, found the problem. 
Manuals for the card (Gigabyte Geforce GTX 980Ti Extreme Waterforce) as both supplied on the CD with the GPU and also as downloadable from the Gigabyte support sites are incorrect / incomplete / wrong model card.
There is a weird button on the end of the card, with an additional 6 pin power socket. This seems to be referenced only on the product details page for Gigabyte as "Built in the LN2 BIOS and extra 6-PIN PCI-E power connectors provide the xtreme overclocking potential by one-click BIOS switch button." Whatever that might mean. Now I only saw this button and socket once I had pulled the card from the computer.
If the LN2 thingy is active, the card doesn't perform. Perhaps it might with added power? That's something for another day. It seems it was active (LED lit red). Deactivate (blue LED) and the card now seems to run fine. Indeed Nvidia inspector suddenly lists all those other performance level options too.
Now with a factory overclock at 1442MHz active on the 980Ti GPU it's chewing those PPS sieve WUS at 5:50 (the 970 managed around 9:50).
Manuals for the card (Gigabyte Geforce GTX 980Ti Extreme Waterforce) as both supplied on the CD with the GPU and also as downloadable from the Gigabyte support sites are incorrect / incomplete / wrong model card.
There is a weird button on the end of the card, with an additional 6 pin power socket. This seems to be referenced only on the product details page for Gigabyte as "Built in the LN2 BIOS and extra 6-PIN PCI-E power connectors provide the xtreme overclocking potential by one-click BIOS switch button." Whatever that might mean. Now I only saw this button and socket once I had pulled the card from the computer.
If the LN2 thingy is active, the card doesn't perform. Perhaps it might with added power? That's something for another day. It seems it was active (LED lit red). Deactivate (blue LED) and the card now seems to run fine. Indeed Nvidia inspector suddenly lists all those other performance level options too.
Now with a factory overclock at 1442MHz active on the 980Ti GPU it's chewing those PPS sieve WUS at 5:50 (the 970 managed around 9:50).
