OctaneRender for Sketchup requires a NVIDIA CUDA-enabled video card with Compute Capability 2.0 or above.
The official list of NVIDIA CUDA-enabled products is located at https://developer.nvidia.com/cuda-gpus.
OctaneRender runs on Maxwell (e.g. GTX 980, Titan) and Pascal (e.g. GTX 1030, GTX 1050) GPUs, including the high-end GTX TITAN and Titan X. It also supports older CUDA enabled consumer video cards (Nvidia GeForce GT 400 series and up) but it will be subject to memory size and speed limitations on those cards. Kepler GPUs allow a higher texture limit (256 compared to 128 on Fermi) and are also more power efficient and more silent than Fermi cards. GPUs from the GeForce line are usually higher clocked and render faster than the more expensive Quadro and Tesla GPUs.
GeForce cards are fast and cost effective, but have less VRAM than Quadro and Tesla cards. OctaneRender scales perfectly in a multi GPU configuration and can use different types of Nvidia cards at once e.g. a GeForce GTX 460 combined with a Quadro 6000.