Genuine Dell AMD MotherBoardFor the Dell Dimension E521 Desktop SystemsDell P/N: YY838, DR830, HK980, CT103, UW457.Features:Chipset: Nvidia GeForce 6150LE.Supported Processors: AMD Athlon 64 X2 dual-core processor, AMD Athlon 64 processor, AMD Sempron processor.Supported Memory: 533-MHz, 667-MHz, 800-MHz (when available) DDR2 SDRAM, Four memory connectors, Capacity: 256 MB, 512 MB, or 1 GB non-ECC, Max Capacity: 4GB.Audio: Sigmatel 9227 CODEC (7.1 Channel audio).Peripheral Interfaces: Video: 15-hole connector, Network adapter: RJ-45 connector, USB: two front-panel and four back-panel USB 2.0-compliant connectors, Audio: six connectors for 7.1 support.Expansion Capabilities:PCI Connectors: 2Connector Size: 124 PinsConnector Data Width (Maximum): 32 bits.PCI Express Connector: one x1Connector Size: 36 PinsConnector Data Width (Maximum): 1 PCI Express Lane.PCI Express Connector: one x16Connector Size: 164 PinsConnector Data Width (Maximum): 16 PCI Express Lanes.Compatible Part Numbers: YY838, DR830, CT103, UW457.