4GB 2RX8 DDR3 1066MHz PC3-8500S 204PIN SO-DIMM Laptop RAM x 2 piece. Frequency: PC3-8500S 1066MHz. Crucial 8 GB DDR3 RAM 2x 4 GB PC3-12800 1600MHz Fr Dell Optiplex 780 790 390_580. Before you order, make sure the RAM is compatible with your motherboard/CPU.
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