Are you a classic Mac afficionado, or someone just looking for a cool looking computer? This elegant case can be utilitized as-is for macOS or can be setup as an excellent NAS box utilizing the 32GB ECC RAM and multiple free SATA slots. This unit has been tested using multiple operating systems and is fully functional. * Intel® Xeon(R) CPU E5520 @ 2.27GHz × 2 * 32GB of 1066MHz DDR3 ECC SDRAM * 18x SuperDrive with double-layer support (DVD±R DL/DVD±RW/CD-RW) * 1GB Seagate HDD (Ubuntu installed) * NVidia Graphics card w/DVI and mini displayport connections * Built-in Bluetooth 2.1 + EDR (Enhanced Data Rate) * Four FireWire 800 ports (two on front panel, two on back panel) * Dual 1GB Ethernet ports * Five USB 2.0 ports (two on front panel, three on back panel) * Front-panel headphone minijack and internal speaker * Optical digital audio input and output TOSLINK ports * Analog stereo line-level input and output minijacks * Tested with macOS Sierra, Windows 10, TrueNAS Scale and Ubuntu (currently installed) * No HDD caddies or accessories included * Three open full-length PCI Express expansion slots5 * One PCI Express 2.0 x16 slot * Two PCI Express 2.0 x4 slots