4GB (2x2GB) RAM Memory Compatible with Dell OptiPlex GX520 Series Desktop | eBay
OFFTEK 512MB Replacement Memory RAM Upgrade for Dell OptiPlex GX520 (DDR2-6400 - Non-ECC) Desktop Memory at Amazon.com
2GB Memory for Dell OptiPlex GX520 DDR2-800 PC2-6400 Desktop DIMM RAM (PARTS-QUICK Brand) at Amazon.com
NeweggBusiness - DELL OptiPlex GX520 Desktop PC Pentium 4 3.0GHz 2GB 160GB HDD Capacity Windows XP Professional 32-bit 3 Years Warranty for School and Colleges only (Verification Required)
4GB kit (2GBx2) Upgrade for a Dell OptiPlex GX520 System (DDR2 PC2-6400, Non-ECC, ) at Amazon.com
DELL OPTIPLEX GX520 NO RAM NO HDD NO OS CHASSIS. REFURBISHED. IN STOCK.
2GB Kit (2 x 1GB) RAM for the Dell OptiPlex GX280 (DDR2-533, PC2-4200) Upgrade at Amazon.com
4GB [2x2GB] DDR2-533 (PC2-4200) RAM Memory Upgrade Kit for The Dell Optiplex GX520 Desktop (Genuine A-Tech Brand) at Amazon.com
Upgrading Ram in the Dell Optiplex Gx520 - YouTube