You can purchase external PCI-E enclosures with a PSU that plugs in to Thunderbolt and you can put pretty much any GPU or any other PCI-E card in there. Some en

You can purchase external PCI-E enclosures with a PSU that plugs in to Thunderbolt and you can put pretty much any GPU or any other PCI-E card in there. Some enclosures permit you to put two or even three cards inside, though the PSU can be quickly overwhelmed. Plug that in to a modern MBP running Windows 7 or Windows 8 and you suddenly have a Windows laptop with a top of the line NVidia card. I was considering going this route for the past two months but was waiting to see what Razer and Alienware announced at CES and sure enough Alienware updated their entire line of laptops to support eGPU, though the Alienware enclosures AFAICS are primarily for GPUs rather than a general-purpose PCI enclosure.