Alienware spawned the micro-tower revolution three years ago with its original X51, squeezing a powerful PC into a chassis only slightly larger than a PS4 or Xbox One. Its sequel, the X51 R3, is getting an upgrade that brings more power and new options into the tiny box.
Most notably, the X51 R3 now has liquid cooling, which attaches a fan and heat-dissipating tubes to the motherboard and CPU, keeping them cool enough to overclock, or run past their rated speed, without harming components. That's important because the X51 is a tiny gaming PC designed to sit on a desk or next to your TV, and overheating can reduce performance.
The R3 also adds a sixth-generation Skylake Intel processor, as well as faster DDR4 memory. Intel's current-gen Core i5 and i7 K-series chips aren't exactly known for being great gaming performers, so it makes sense to upgrade them. The i7 chip in this particular model can be overclocked to 4.4GHz with the help of an all-in-one liquid cooler.
However, because of the X51's 350W cap via an external power supply that's about the size of an Xbox One's brick, you can't just toss in a beefier GPU like a GTX Titan. To address that, the X51 R3 now supports an optional Graphics Amplifier, an external metal housing that holds a desktop graphics card and connects to the X51 using a special port and cable. This lets you run up to a GeForce GTX 970 in the Graphics Amplifier, although that'll significantly raise the cost of your system.