SPEAK TO OUR LENOVO SOLUTION TEAM : 
System X3500 M5 Tower
All-in-one two-socket tower server (with available 5U rack mount), with big performance & storage configurations in a small footprint for business-critical enterprise workloads.
•Tower (5U rack-mountable)• Up to 2 Intel® Xeon® E5-2600 v3 series processors / 36 cores
• Up to 1.5 TB
System x3100 M5 Tower
4U/5U tower server that delivers business-class performance, energy efficiency, & reliability in a compact tower.
• 4U/5U (model dependent)• Intel® Xeon® E3-1200 v3 series (quad-core) OR Intel® Core; i3 series (dual-core) OR Intel® Pentium® series (dual-core) OR Intel® Celeron® processor (dual-core)
• Up to 32 GB / 4 DIMMs
• Up to 24 TB