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Solved: 390, CPU upgrades? - Page 4 - Dell Community
Dell Optiplex 390 Upgrade RAM, SSD, DVD Drive - YouTube
Restored Dell OptiPlex 390-T Desktop PC with Intel Core i5-2400 Processor, 8GB Memory, 500GB Hard Drive and Windows 10 Home (Monitor Not Included) (Refurbished) - Walmart.com
8GB (2 X 4GB) Memory Upgrade for Dell Optiplex 390 DDR3 PC3-10600 1333MHz Desktop DIMM RAM (PARTS-QUICK Brand) at Amazon.com
Dell Optiplex 390 Mini Tower Intel Core i3-2130 @ 3.40GHz 8GB RAM No H
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4GB Memory Upgrade for Dell Optiplex 380, 390 DDR3 PC3-10600 Desktop RAM (PARTS-QUICK Brand) at Amazon.com