PNY manufactures 512MB SDR memory upgrades rated at PC-100 and PC-133. They are compatible with desktop and notebook computers and processors such as Intel’s Pentium II/III and Celeron, AMD’s K6-2, Athlon, and others. PNY memory upgrade modules are compatible with systems from Apple, Compaq, DELL, Gateway, HP, IBM and over 5000 other systems. Boost the performance of your PC. PNY memory upgrades will prove to be an outstanding value now and in the future. Important: Consult your PC manual. 512MB upgrade may not be supported by all systems.