Juanjo,
It's been a long time but I'm glad to be back. Last couple of days I've been enjoying using Octane again and enjoying its splendid results.
But I have a couple of small issues connected with the GPUs options. Firstly, I'm totally up-to-date with software versions with Windows, LightWave, most recent plugin 2019.1 version. I have two Titan Blacks. During rendering, when I open Task Manager and monitor their performances, both of them do seem to be working but only the one with my displays connected actually outputs utilization data. I'm pretty sure the other one is working too, but Task Manager doesn't report. It stays at 0%. I know this is probably a Windows bug, but I'm just wondering if you've ever noticed this too.
The other thing is, I generally like to keep image quality at maximum so I tend to always choose "untonemapped" when asked in output, but in the plugin options, GPUs tab, I don't understand what the "Use Tonemap" buttons are for. My intuition tells me to turn them off, but when I come back I find that they've turned themselves back on!
Best wishes, Hal Dace