This is an awesome video showcasing the extreme speed at which Octane Render is able to produce photorealistic images with path tracing (and it's also a nice introduction to Octane). Coffeemills will never be the same after you've seen this:
And this one shows off the powerful material system in Octane, and it's all rendered at full photorealistic quality in real-time:
A short real-time test in Stonemason's Backstreets: