like aoktar said, it could be a VRAM issue. depending on how large your scene is, opening photoshop and other GPU / VRAM intense apps (even certain websites with safari) can eat up a lot of free VRAM and make cinema + octane unresponsive. had the same experience here with larger scenes, given a 980ti card with 6G of VRAM with medium to large scenes.
also, try to make your cinema scene as slim as possible. for example by optimizing all textures, that's the biggest footprint. set as much as you can to grayscale (float) and keep them as small as detail will needed. large geometry seems not to affect footprint too much.
tips for an interactivity speed up include to switch off automatic conversion of materials for opengl, but it will remove the preview in your viewport. also monitor that your system has enough free RAM and your memory scratch disk (usually boot volume, if not set to other by some utility) has enough free space. cinema's automatic backup can fill up a disk very fast if you don't care to put project files on a separate partition / drive. it all depends on your hardware configuration, of course.
cheers
markus