Series/Family: Intel Xeon Processor E5 v4 Family, Supported Socket : LGA2011-3, Total Cores : 4, PCI Express Version: 3.0, Memory Types: Up to DDR4 1600/1866/2133 MHz, Total Threads : 8, Max Turbo/Boost Clock : 3.20GHz, Base Clock: 2.60GHz. The Xeon E5-2623 v4 2.6 GHz 4-Core LGA 2011 Processor from HP can be used as a 2nd CPU for the HP Z640 Workstation. It has a base clock speed of 2.6 GHz and comes with features such as Intel Turbo Boost 2.0 and Intel Hyper-Threading technology.