 The 100, 200, 300 and 400 series comprise single and dual socket capable systems, the 500 and 600 series comprise quad socket capable systems, and the 700 and 900 series comprise eight socket capable systems.The 900 series supports up to 80 CPU cores and up to 4 TB of RAM.Models with a '0' in the last digit use Intel processors while models with a '5' in the last digit use AMD processors.