Colour Profile isn't available in the scatter position shader to change to linear.
Version 3.07-R2 Mac (can't upgrade either as Cuda/GPUs aren't found)

SOLVED:

Reset fontbook
Use Internet Octane Details (new login details etc)

switching off 'use all gpus', then testing the render times by switching cards on/off did show speed increase, but it seems to be inversely exponential gains not linear,
i.e.
(2000x1000@1000samples with Pathtracing)
1 Card = 30 secs
2 Cards = 20 secs
3 Cards = 15 secs
4 cards = 13 secs

thanks for clarifying info!

I currently have 4x780ti, just wondering how the 1080 ti would perform in comparison.
(would greatly reduce clutter/heat/power usage etc if it's comparible)

thanks

i have 4 x EVGA GTX 780 ti and haven't noticed any increase in speed.
i've switch on/off different cards in the options and still get the same render times.

i'll do more testing, but i haven't noticed a different going from 1 to 4 over the period of time of acquiring the cards.

Thanks to "bepeg4d"
please give him a raise

SOLVED!

1. reset FONTBOOK to default
2. use OTOY login data NOT license data (if on version 3)

it fixed the font issue,
but it still says invalid input?

good idea.
it looks like it's already installed, however fontbook is buggy (crashes etc)
maybe ill look into that, reinstall to defaults etc.

i wouldnt think that it's the culprit though as technically the correct info was used to activate.
ill try though and get back to you.
thanks for the ...