The allocation of CPU/GPU depends on the rendering mode you have chosen. Quality is more likely (almost always, in my experience) to use the CPU while Advanced is more likely to use the GPU.
If you are using RedSDK, you can get more GPU rendering. Also, when moving/rotating/etc., the display will always use Draft mode until you stop, then it will re-render.
TC Pro Platinum 2019, 2018, 2017, 2016 & 2015 (all with LightWorks & RedSDK) & V21
System: i7-5820K @ 3.30GHz, ASRock X99 Extreme4, 16GB DDR4-2133 RAM, Gigabyte GTX 970, Samsung NVMe SSD 950 (256GB), Windows 7 Pro (64-bit) SP1