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CS4 and 64-bit Systems, Part 1

Dec 8, 2008 12:00 PM, By Jan Ozer

           

HP xw8600

What is 64-bit computing?

There are multiple differences between 32-bit and 64-bit processors, but the most important in this application is the size of the memory that the processor can address. 32-bit processors can address 2³² bytes, which translates to 4GB of memory. That’s why the maximum amount of RAM you’ll see on most 32-bit Windows systems is 4GB, though some of this is reserved for the operating system. In contrast, 64-bit processors can address 2⁶⁴ bytes, which translates to 16 exabytes of memory, though Windows Vista x64 is limited to 128GB of RAM.

To run in 64-bit mode, you need a 64-bit processor and a 64-bit operating system. The original x86-64 specification was designed by AMD, and adopted by Intel with its Core 2 Duo and later processors. Microsoft has long offered 64-bit versions of both XP and Vista, and Apple dipped its toe in the 64-bit waters with Tiger and jumped in with Leopard.

Note that 32-bit applications can run inside of a 64-bit operating system, but they still can only address a maximum of 4GB of memory. In contrast, a true 64-bit application can theoretically address the maximum amount of memory supported by the operating system.

Getting to 64-bit Windows

You can get to 64-bit Windows a couple of ways. First, you can upgrade your current system if it has a 64-bit processor. However, while 32-bit application programs run under 64-bit versions of Windows, you’ll also need 64-bit drivers for graphics cards, hard disks, DVD recorders, and other hardware devices; otherwise, you won’t be able to use them. In addition, if you can’t increase your RAM to at least 8GB of memory, you may not realize many of the benefits of 64-bit computing.

The other approach, of course, is to buy a new 64-bit system. Obviously, in this case, all the drivers will be 64-bit, and you’ll probably have the ability to add more RAM than you could with an older 32-bit system.