CPU Model: Intel ATOM C3538, CPU Architecture: x64 64-bit, CPU Frequency: Quad-Core 2.1GHz, Memory: 8GB SO-DIMM DDR4 Compatibility, Memory Module Pre-installed: 8GB (1 x 8GB), Total Memory Slots: 4, Flash Memory: 8GB eMMC, Drive Bays: 4, Maximum Drive Bays with Expansion Unit: 20, Expansion: USB 3.2 Gen 1 x 4, HDMI Output: N/A, System Fan: 40mm x 2, Input Power Voltage: 100V to 240V AC, Warranty: 3 Years A thin 1U rack 2.5GbE server providing stable performance and four bays for expandable and easy SATA storage. The Lockerstor 4RS and 4RD bring expandability by bringing PCI Express capabilities