Datasheet

Protected memory

Protected memory isolates applications in their own individual memory workspaces. When an

application crashes, the program can be terminated without having a negative effect on other

running applications or requiring a restart of the computer.

Advance memory management

Advance memory management automatically manages physical RAM and virtual memory dynami-

cally as needed. Virtual memory uses hard disk space in lieu of physical RAM. Information that

would normally sit in RAM, but is not currently needed, is transferred to the hard disk to free up

physical RAM for the demands of data/applications that need it. This alleviates out-of-memory con-

ditions and eliminates the need, experienced by users of previous Macintosh desktop operating

systems, of having to manually adjust memory allocations.

Preemptive multitasking

Mac OS X, like all Mac OS versions since System 7, allows more than one application to be open

and operating at the same time. This capability is known as

multitasking. Prior to OS X, the Mac OS

employed a version of multitasking referred to as

cooperative multitasking. In cooperative multitask-

ing, applications sometimes seemed unresponsive because the system software could not efficiently

manage the concurrent demands of multiple running programs. Mac OS X remedies this by imple-

menting

preemptive multitasking. Preemptive multitasking prioritizes processor tasks by order

of importance. This more efficient method of managing processor tasks allows the computer to

remain responsive, even during the most processor-intensive tasks.

Symmetric multiprocessing

Symmetric multiprocessing (SMP) provides support for multiprocessor Macintosh computer sys-

tems. This allows applications to take advantage of two or more processors by assigning applications

to specific processors or by splitting parts of applications, known as

threads, between multiple

processors simultaneously. Mac OS X is further optimized to take advantage of SMP by employing

a technique known as

optimized kernel resource locking. Optimized kernel resource locking provides

superior SMP performance by allowing multiple CPUs access to different portions of the kernel

simultaneously. Mac OS 10.5 takes multiprocessing another step forward with its multicore proces-

sor competency, allowing it to harness the power of up to eight cores simultaneously, which is the

maximum number of cores shipping inside of Macintosh computers at the time of this writing.

Graphics technologies in Mac OS X

When it comes to graphics, Mac OS X is one of the most powerful operating systems on the planet.

To achieve this power, Mac OS X employs several standards-based technologies that are best-of-

class. These technologies include Quartz, OpenGL, and QuickTime. Over the past couple of years,

some of the greatest strides in hardware performance have come in the form of video hardware.

Mac OS X 10.5 has been optimized to take advantage of this high performance video hardware.

Designated as Core Image and Core Animation, this software optimization improves performance

Introduction and Installation of Mac OS X

05_041741 ch01.qxp 2/2/08 12:08 AM Page 5