Physical Address Extension facts for kids
A computer's brain, called the CPU, needs to talk to its memory (RAM) to do its work. Physical Address Extension (PAE) is a special feature that helps older 32-bit CPUs use more RAM than they normally could.
Imagine your computer's CPU can only count up to 4 billion things (4 gigabytes) when it talks to memory. PAE helps it count much higher, up to 64 billion things (64 gigabytes)! This means your computer can use a lot more RAM, which helps it run many programs at once or handle very large files.
PAE was first added to Intel processors like the Pentium Pro. Since then, most Intel processors have had this feature. AMD processors also started supporting PAE with their Athlon chips. For PAE to work, both the CPU and the operating system (like Windows or Linux) need to support it. Windows 2000 was one of the first operating systems to use PAE.
How Computers Use More Memory
Computers use special "addresses" to find information in their memory. Older 32-bit CPUs could only create addresses for up to 4 gigabytes of RAM. This was fine for a long time, but as programs got bigger and people wanted to do more things at once, computers needed more memory.
PAE helps by giving the CPU a way to use longer addresses. Think of it like adding more digits to a phone number. With more digits, you can have many more unique phone numbers. In the same way, PAE allows the CPU to access a much larger amount of physical memory. This is especially useful for servers or powerful workstations that need a lot of RAM to run smoothly.
Processors That Use PAE
Many different computer processors support PAE. This table shows some common processors and how much memory they can address with PAE. The "Physical Addressing Bit Width" tells you how many "digits" the processor can use for memory addresses. More bits mean it can address more memory.
Processors | Physical Addressing Bit Width |
---|---|
Intel Pentium Pro/Pentium II/Pentium III/Pentium II Celeron/Celeron | 36 bits |
Intel Pentium 4/Pentium 4 Celeron/Pentium D/Celeron D | 36 bits |
Intel Core 2/Pentium Dual-Core/Celeron | 36 bits |
Intel Core i3/i5/i7/Celeron/Pentium | 36/39 bits |
AMD Athlon 64/Athlon X2/Sempron/Sempron X2 | 40 bits |
AMD Athlon/Athlon II/Sempron/Sempron X2 | 48 bits |
AMD C-50 | 36 bits |
AMD APU A4/A5/A6/A8/Athlon/Sempron | 48 bits |
See also
In Spanish: Extensión de dirección física para niños