There are plenty of workstation laptops that claim to deliver on the promise of heavy-duty computing on the road, but they're not usually that much different on the inside than a garden variety portable. You can't say that about Lenovo's monster new ThinkPad P50 and P70 systems, though. The two not only offer things you'd expect in this class, such as color-accurate 4K displays and pro NVIDIA Quadro graphics, but Intel's first-ever mobile Xeon processors (specifically, the E3-1500M) -- you won't have to settle for an ordinary Core i-series chip here. If you need to crunch 3D models or video when you're out of the office, one of these rigs may be your best bet. That CPU upgrade also brings the kind of perks normally limited to desktops, including support for a whopping 64GB of memory and Thunderbolt 3 ports that can handle dual 4K displays.