
Since 2001, the breakthrough technologies and
rock-solid UNIX foundation of Mac OS X have made it not only the world’s
most advanced operating system but also extremely secure, compatible,
and easy to use. Snow Leopard continues this innovation by incorporating
new technologies that offer immediate improvements while also smartly
setting it up for the future.
New in Snow Leopard:
More secure than ever.
Another benefit of the 64-bit applications in Snow Leopard is
that they’re even more secure from hackers and malware than the 32-bit
versions. That's because 64-bit applications can use more advanced
security
techniques to fend off malicious code.
First,
64-bit applications can keep their data out of harm's way thanks to a
more secure function argument-passing mechanism and the use of
hardware-based execute disable for heap memory. In addition, memory on
the system heap is marked using strengthened checksums, helping to
prevent attacks that rely on corrupting memory.
64-bit applications in Snow Leopard deliver faster performance at common operations.²
32-bit compatible.
To ensure simplicity and flexibility, Mac OS X still comes in
one version that runs both 64-bit and 32-bit applications. So you don’t
need to update everything on your system just to run a single 64-bit
program. And new 64-bit applications work just fine with your existing
storage devices, PCI cards, and Snow Leopard-compatible printers.
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64-bit computing used to be the province of
scientists and engineers, but now this generational shift in computing
gives all users the tools to apply the power of 64-bit to speed up
everything from everyday applications to the most demanding scientific
computations. Although Mac OS X is already 64-bit capable in many ways,
Snow Leopard takes the next big step by rewriting nearly all system
applications in 64-bit code¹ and by enabling the Mac to address massive
amounts of memory. Now Mac OS X is faster, more secure, and completely
ready for the future.
The 64-bit transition.
The entire computing industry is moving from 32-bit to 64-bit
technology, and it’s easy to see why. Today’s Mac computers can hold up
to 32GB of physical memory, but the 32-bit applications that run on them
can address only 4GB of RAM at a time. 64-bit computing shatters that
barrier by enabling applications to address a theoretical 16 billion
gigabytes of memory, or 16 exabytes. It can also enable computers to
crunch twice the data per clock cycle, which can dramatically speed up
numeric calculations and other tasks. Earlier versions of Mac OS X have
offered a range of 64-bit capabilities. Now Snow Leopard takes the next
step in the transition from 32-bit to 64-bit.
Built-in applications are now 64-bit.
Nearly all system applications — including the Finder, Mail,
Safari, iCal, and iChat — are now built with 64-bit code. So not only
are they able to take full advantage of all the memory in your Mac, but
the move to 64-bit applications also boosts overall performance.
Together with other
refinements and improvements
in Snow Leopard, this means that just about everything you do — from
launching applications like QuickTime to running JavaScript in Safari to
opening image files — will feel faster and more responsive.
Ready for the future.
The 64-bit support in Snow Leopard makes Mac OS X completely
ready for whatever computing enhancements might arrive in the future.
For example, Snow Leopard is ready to support up to 16 terabytes of RAM —
about 500 times more than today’s Mac computers can accommodate. That
may sound like more RAM than you’ll ever need, but who can predict the
requirements of high-performance computers in the future? Mac OS X Snow
Leopard comes prepared for anything.
More cores, not faster clock speeds, drive
performance increases in today’s processors. Grand Central Dispatch
takes full advantage by making all of Mac OS X multicore aware and
optimizing it for allocating tasks across multiple cores and processors.
Grand Central Dispatch also makes it much easier for developers to
create programs that squeeze every last drop of power from multicore
systems.
With CPUs, more cores is better.
In the past, the best way for computer chip makers to improve
performance was to turn up the clock speed on the processor. But that
generates more heat and consumes more power, which is bad for computers,
especially notebooks. So instead the industry has moved to chips with
multiple processor cores, which can provide more performance while
consuming less power. Today every Mac runs on one or more multicore
Intel processors.
Multicore. Multiple challenges.
To take full advantage of these processors, software
applications must be programmed using a technology called threads.
Software developers use threads to allow multicore processors to work on
different parts of a program at the same time. However, each
application must do its own threading, which reduces the efficiency of
the entire system. And because threads can be difficult to program, many
developers don’t invest the effort to make their applications multicore
capable. Consequently, lots of applications aren’t as fast as they
could be.
Introducing Grand Central Dispatch.
Grand Central Dispatch (GCD) in Mac OS X Snow Leopard addresses
this pressing need. It’s a set of first-of-their-kind technologies that
makes it much easier for developers to squeeze every last drop of power
from multicore systems. With GCD, threads are handled by the operating
system, not by individual applications. GCD-enabled programs can
automatically distribute their work across all available cores,
resulting in the best possible performance whether they’re running on a
dual-core Mac mini, an 8-core Mac Pro, or anything in between. Once
developers start using GCD for their applications, you’ll start noticing
significant improvements in performance.
A finely tuned engine.
Grand Central Dispatch is extremely efficient at what it does.
It dynamically scales the workload of an application to account for the
number of processors in the computer. And it makes applications more
efficient by using only the number of threads required for the work
being done. For example, without GCD, if an application needs 20 threads
when at maximum capacity, it might set up 20 threads and consume the
associated resources even when it has nothing to do. GCD, by contrast,
frees resources when it’s not using them, helping to keep the whole
system more responsive. Imagine the efficiency and performance gains if
every application on your Mac were using GCD.
Built into the core.
Grand Central Dispatch is deeply integrated into Mac OS X Snow
Leopard, making it easier for all kinds of applications to take better
advantage of multicore processors. In addition, your Mac as a whole
becomes more efficient at handling numerous tasks at the same time,
resulting in performance gains across the board.
Developers will program for Grand Central Dispatch using the
Xcode tools included with every Mac. They can use the Xcode debugger and
Instruments performance analysis tool to get insights into GCD at
runtime. These tools make it possible to quickly inspect any GCD work
queue, even down to a specific block of executing code, giving
developers a complete understanding of their application as GCD
efficiently assigns tasks to each available core.
With graphics processors surpassing speeds of a
trillion operations per second, they’re capable of considerably more
than just drawing pictures. OpenCL in Snow Leopard is a technology that
makes it possible for developers to tap the vast gigaflops of computing
power currently in the graphics processor and use it for any
application.
The skyrocketing power of GPUs.
Over the last few years the performance of graphics processing units (GPUs) has
grown exponentially as measured in gigaflops. Today’s fastest GPUs are
capable of over one teraflop, as much as the room-size ASCI RED
supercomputer of just 12 years ago.
A graphic shift in performance.
Now a new technology in Mac OS X Snow Leopard called OpenCL
takes the power of graphics processors and makes it available for
general-purpose computing. No longer will graphics processors be limited
to graphics-intensive applications such as games and 3D modeling.
Instead, once developers begin to use OpenCL in their applications,
you’ll experience greatly improved speed in a wide spectrum of
applications.
For example, sophisticated financial modeling techniques can be
incorporated into desktop accounting software and personal finance
software. Media applications can perform complex, intensive operations
with larger video and graphics files. Games can have more realistic
physics simulations. And scientists and researchers can tackle far more
challenging problems using their everyday Mac computers.
Optimized for the task.
OpenCL automatically optimizes for the kind of graphics
processor in the Mac, adjusting itself to the available processing
power. OpenCL provides consistent numeric precision and accuracy, fixing
a problem that has hampered GPU-based programming in the past.
Familiar, C-based language with industry support.
OpenCL stands for Open Computing Language. It’s a C-based
programming language with a structure that will be familiar to
programmers, who can simply use Xcode developer tools to adapt their
programs to work with OpenCL. They don’t have to completely rewrite
applications to use OpenCL. They need only rewrite the most
performance-intensive parts of their application in OpenCL C. The vast
majority of application code can be left unchanged. Best of all, OpenCL
is an open standard that’s supported by the biggest names in the
industry, including AMD, Intel, and NVIDIA.
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Snow Leopard introduces QuickTime X, a major leap
forward that advances modern media and Internet standards. QuickTime X
includes a brand-new player application, offers optimized support for
modern codecs, and delivers more efficient media playback, making it
ideal for any application that needs to play media content.
Another leap forward.
QuickTime X is the next-generation media technology that powers the audio and video experience in Mac OS X Snow Leopard. From
its inception in 1991, QuickTime has stood at the forefront of video
technologies — first with software-based video, then with Internet
video. Now QuickTime X takes another leap forward by building on the
amazing media technologies in Mac OS X — such as Core Audio, Core Video,
and Core Animation — to deliver enhanced playback, greater efficiency,
and higher quality.
A new QuickTime Player.
QuickTime X debuts a brand-new version of QuickTime Player, the
standalone application used by millions to watch QuickTime-based video.
Using the power of the Core Animation technology in Mac OS X, QuickTime
Player offers a clean, uncluttered interface with controls that fade out
when they’re not needed. And large thumbnail images make navigating
chaptered movies simpler than before.
With a single click, QuickTime Player can now capture audio or
video using the built-in camera and microphone in your Mac. You can
easily trim media to the perfect length, then send it to iTunes for
syncing to an iPhone, iPod, and Apple TV. You can also use QuickTime
Player to publish your media to MobileMe or YouTube — without worrying
about codec formats or resolutions.
Built for smooth playback.
QuickTime X is optimized for the latest modern media formats —
such as H.264 and AAC — through a new media architecture that delivers
stutter-free playback of high-definition content on nearly all Snow
Leopard-based Mac systems. QuickTime X maximizes the efficiency of
modern media playback by using the graphics processor to scale and
display video. QuickTime X further increases efficiency by supporting
GPU-accelerated video decoding of H.264 files.
Video streaming from any server.
QuickTime X takes Internet video streaming to new levels with
support for HTTP live streaming. Unlike other streaming technologies,
HTTP live streaming uses the HTTP protocol — the same network technology
that powers the web. That means QuickTime X streams audio and video
from almost any web server instead of special streaming servers, and it
works reliably with common firewall and wireless router settings. HTTP
live streaming is designed for mobility and can dynamically adjust movie
playback quality to match the available speed of wired or wireless
networks, perfect whether the video is watched on a computer or on a
mobile device like iPhone or iPod touch.
High performance, high quality.
Because it’s built into the heart of Snow Leopard, QuickTime X
uses Mac OS X technologies such as Cocoa, Grand Central Dispatch, and
64-bit computing to deliver greatest-possible performance and enables
QuickTime Player to launch up to 2.4x faster.
2 QuickTime X
also takes advantage of ColorSync to provide high-quality color
reproduction during playback and when sharing media to your iPhone,
iPod, or Apple TV.
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