An external GPU can be separately cooled outside the computer itself. TB3 allows for an arbitrary number of external GPUs. Imagine buying a thing that looks like a small micro-fridge, that you attach to your laptop over a long TB3 cable. Your GPUs stay at sub-zero temperatures while you game, and now your cooling system only has to take care of the CPU itself—a much easier proposition. An external GPU architecture removes the limitation on the number of available slots a computer might internally have, so that something like SLI or Crossfire could be accomplished by simply stacking some bricks and hooking up some cables to a laptop. Macs have never had SLI or Crossfire because we never had a system with multiple 16-lane PCI slots. But now we'll be able to have a laptop attached to a stack of four external TB3 NVIDIA Titan2 GPUs and two curved 4K monitors. Holy crap YES. An external GPU architecture allows the GPU company to be responsible for warrantying their GPUs. That way if NVIDIA has a batch of bad GPUs, rather than have to do surgery on your laptop or iMac. Neither Apple nor their customers ever want to experience down time or have their computer torn apart—I should know, I've been through multiple service calls and lost countless hours of work to downtime caused by defective NVIDIA components in a MacBook Pro and an iMac that I own. Preliminary results from people who have attached external Thunderbolt 2 enclosures with GPU cards in them to MacBook Pros and iMacs have been very positive, as I mentioned in a post above. So I think this whole eGPU thing is going to absolutely explode. We're going to look back on internal GPUs as a laughable relic of the past. So in a way, while we all think that Apple has been ignoring desktop gaming in favor of iPads etc., in fact, they have (whether intentionally or not), been driving us towards the future of gaming—external GPUs—and they will be the first manufacturer with Thunderbolt 3 on the market. Once the public realizes that external GPUs are actually a viable option, they will start demanding them, because external GPUs are a hugely better idea than internal ones for the above reasons. So, considering all of this, how bright is OS X's future as a gaming platform, especially considering Metal is now on OS X? Or will TB3 eGPUs not end up being popular, I'm wrong, and Mac users will suffer forever with GPU-less machines and no good games forever?