In computing, Physical Address Extension (PAE) allows for up to 64 gigabytes of memory to be used in 32 bit systems, given appropriate operating system support. PAE is provided by Intel Pentium Pro and above CPUs (including all Pentium-series processors except the original Pentium and the Pentium MMX), as well as by some compatible processors such as those from AMD. The CPUID flag PAE is assigned for the purpose of identifying CPUs with this capability.