Cn-0Y5638 Dell System Board For Optiplex Gx280 Genuine Dell motherboard model XF954 for OptiPlex GX280 Tower Cases Intel 915 Express ChipSet, Socket LGA775 Supporting Pentium 4, Celeron, Prescott Processors up to 3.2ghz, Hyper-Threading Technology Support , 533/800 MHz system bus 4 Dual Channel DIMM Support for DDR2-400/533, 4 GB MAX system memory , 1 16x PCI-Express Video Slot , Integrated Intel 900 Graphics Accelerator , Integrated 10/100/1000 Lan , Integrated ADI Sound , 2 Serial ATA Hard Disk Connectors, One ATA-66/100/133 IDE Hard Disk Connector , One Floppy Connector 3 PCI Card Slots, 1 1X PCI Express, 6 USB 2.0 Ports, Audio Ports for line-in, line-out, and microphone , 1 Serial/1 Parallel Port, PS2 Mouse and Keyboard Ports