The Asus ESC4000 G3 is a barebones 2U server designed to provide a combination of CPU and co-processor computing in a compact, rackmount form factor. It comes with a proprietary motherboard that supports dual Xeon E5 V3 and V4 series processors and the layout inside the system allows for a tremendous eight single-width, full-height, full-length expansion cards (or four dual-width cards).