Laptops are getting thinner and thinner, not to mention sometimes converting into tablets. But the price of portability is performance, at the very least graphics performance. There are, of course, a new breed of computing accessories that deliver added graphics processing power via Thunderbolt 3 but those are heavy in both price and form. Enter the Lenovo Thunderbolt 3 Graphics Dock somewhat quietly revealed at CES 2013. No larger than a laptop, this graphics card enclosure claims it’s powerful enough to even run Windows Mixed Reality at 90 Hz rates. But, of course, there’s always a catch.