Let's discuss the technical issues with Thunderbolt GPU support. The most promising external GPU work is at Silverstone, who recently demonstrated a work in progress MSI also has something they're working on, but inexplicably they didn't include power. Does this case make sense? The Anandtech Mac Pro review states that PCIe 3.0 x16 channels is 15.7 GB/s bandwidth. Going further in the review he shows TB 2.0 as having 2.5 GB/s of bandwidth - quite a difference. However, consider that with TB 1.0 half of the bandwidth can be used for video output, namely 1.25 GB/s. That's the theoretical max, but we can assume that displaying pixels on a 27" 2560x1440 screen at 30 Hz or 60 Hz takes no more than 1.25 GB/s. So the question is, does that really require 15.7 GB/s on the input? What are all those PCIe x16 lanes for anyhow? Loading the VRAM (RAM->VRAM DMA), serving interrupts (CPU->GPU), and inter-card communication (SLI/Crossfire) AFAIK. Now we can eliminate the final use case as this would be a single card only solution, though theoretically somebody could actually make a two slot external TB2.0->PCIe GPU box with two x16 lanes. Are 16 lanes really needed for loading VRAM and serving interrupts? So here my knowledge and searching pans out. My question is whether this analysis is accurate, and whether this kind of device can work? The remaining piece for SilverStone is to get Intel certification, and OS X thunderbolt aware drivers.