Is dual-GPU. Each NCU houses 64 steam processors, of which the Vega 56 has 3584 vs. 4096 in the Vega 64. Peripheral Component Interconnect Express (PCIe) is a high-speed interface standard for connecting components, such as graphics cards and SSDs, to a motherboard. AMD Radeon RX 580. The Radeon RX Vega 56 is the weakest member of AMD's Vega GPU family. The new architecture employs 8GB of second generation high-bandwidth memory (HBM2). Newer versions can support more bandwidth and deliver better performance. AMD Radeon RX Vega 56. 5. The Vega architecture is built on 14 nm silicon and contains next-generation compute units (nCUs).