Does OSX have a memory limit?

You can install up to 16GB of RAM on a Mac Pro.

Up to 2GB on an 1.83 GHz iMac and up to 3GB on an iMac 2.0 GHz and up.

Up to 3GB on a MacBook Pro.

Up to 2GB on a MacBook.

I don't believe Tiger determines the RAM limitation - obviously not if you can install up to 16GB of RAM on a custom build to order Mac Pro.

Edit - up to 16GB of RAM on a Mac Pro which has two processors.

It is the 32-bit chipset that causes a RAM limitation of 4GB.

But aren't those all the hardware limitations to the computer?

Yes.

I'm not sure about an OS X operating system limitation for RAM.

The limits are the same-hardware and software-and refer to the ability to address the memory.

If you have a 32bit operating system, it's limited by the same 4GB limit (2^32=4,294,967,296).

If you have a 64bit operating system (such as OS X Tiger) running on a 64bit computer, it's theoretically limited to about 17 Billion GB.

So, with Tiger, you're not likely to run into a memory limit anytime soon.
http://www.apple.com/macosx/features/64bit/

Hi Topher Macintosh;

Since OS X is capable of using 64 bit addressing that means the maximum addressable space for the operating system would be 16 exabytes. Granted no hardware is capable of containing that nor do I think any of us can afford to purchase that much memory.


Allan

If you have a 32bit operating system, it's limited by
the same 4GB limit (2^32=4,294,967,296).

A 32-bit OS can still use more than 4GB, but no single application can use more than 4GB.