Octane does support using multiple cards for rendering (not in SLI mode though, they have to work as separate cards). But that currently depends on whether your card works with the CUDA 3.0 drivers or not. CUDA 3.0 version of Octane supports multi-gpu rendering and CUDA 3.2 version of Octane currently doesn't (NVIDIA made some changes to cuda that broke Octane's multi-gpu code, they are fixing it). I know the 480 and 470 cards are compatible with C3.0, so perhaps 460 is too.