[Ti] Using a separate swap partition?

[Chris Olson]

On Nov 11, 2004, at 3:44 AM, Lisbeth Zachs wrote:

> I do. Since I'm still with the PB G4 400 (though with a speedier new  
> HD) I feel I benefit from having PhotoShop and PS Elements swap around  
> on a separate partition. Even more so since my extra 256 MB SDRAM  
> failed and I'm down to 512 MB SDRAM.

Traditional Unix systems use separate swap partitions, and <=OS 9  
benefited from a scratch disk for applications like Photoshop.  Mac OS  
X has no need for separate swap partitions, and any benefits from using  
a separate swap partition are perceived only.  I've run some extensive  
benchmarks measuring file system thruput and memory paging performance  
on the server version of OS X, running as a heavily loaded MySQL  
database server, and in most instances you actually *loose* performance  
with a swap partition.

In Mac OS X, the Mach kernel is *designed* to use the root partition  
for swap space.

Perhaps anyone convinced separate swap partitions enhance performance  
should study the developer documentation on memory management and  
programming for the Mach kernel (long URL - might have to cut and  
paste):
http://developer.apple.com/documentation/Darwin/Conceptual/ 
KernelProgramming/index.html?http://developer.apple.com/documentation/ 
Darwin/Conceptual/KernelProgramming/About/chapter_1_section_1.html

--
Chris