Dell Motherboard U2313 OptiPlex SX280 HM781 D8695 Works With the Following Systems : Dell OptiPlex SX280 Dimensions 8.9 cm (3.5 inches), 25.3 cm (9.95 inches), 26.4 cm (10.375 inches) Processor Support for an Intel® Pentium® 4 processor in a LGA775 socket with a 400 / 533 / 800 MHz system bus Support for an Intel® Celeron® D processor in a LGA775 socket with a 400 / 533 MHz system bus Memory Two DDR2 240Pin DIMM sockets Support for single-sided or double-sided DIMMs (DDR2 533/400/333/266) 2GB Maximum Memory Support ( Dual Channel Mode ) Supports 128MB, 256MB, 512MB or 1GB NON Ecc Memory Sticks Chipset Intel® 915G Chipset Sound On Board Sound Blaster emulation Stereo Sound - Line In, Line Out, Microphone Video On Board Intel 2D/3D Graphics Accelerator DVI-I Output Peripheral Interfaces Five Back-panel USB 2.0 ports and Two Front-panel USB Ports. USB 1.1 Compatible One serial port One parallel port Gigabit network port capable of 10/100/1000 communication One SATA Port Compatible Part Numbers: U2313 , 0U2313 , UH789 , 0UH789 , D8695 , 0D8695 , UD789 , 0UD789 , HM775 , 0HM775 , DU683 , 0DU683 , WH415 , 0WH415 , JT105 , 0JT105