|
64-Bit Windows Overview
|
|
Posted: Thursday, October 07, 1999
Contents
The 64-bit Windows® operating system represents a
key milestone in 64-bit technology development. In keeping with the vision of
delivering a higher-performing, scalable, and more feature-rich operating system
to the market, Microsoft has made the Windows 2000 code base 64-bit ready and is
working toward delivering a fully featured 64-bit operating system in 2000. This
will be fully compatible with existing 32-bit applications.
Microsoft is also accelerating application development
on the 64-bit Windows platform by assisting independent software vendors (ISVs)
in their development process. To help ISVs and application developers get a
jump-start today, Microsoft is providing 64-bit platform development tools in
the Windows 2000 Software Developers Toolkit (SDK) and Device
Driver Toolkit (DDK). SDK
and DDK provide the tools needed to easily port applications to the new IA-64
systems as soon as they become available commercially.
The 64-bit Windows platform will provide high
availability, advanced scalability, and large memory support based on the Intel
64-bit chip with its extensive multiprocessing features, powerful floating-point
arithmetic extensions, and multimedia-specific instructions. 64-bit Windows and
the IA-64 microprocessor are designed to address the most demanding business
needs of today's Internet-based world including e-commerce, data mining, online
transaction-processing, memory-intensive high-end graphics, complex mathematics,
and high-performance multimedia applications. Microsoft's vision is to make a
broad portfolio of applications available, including leading Microsoft
applications on 64-bit Windows. To achieve this goal, Microsoft will provide a
rich set of development tools that will make it easy to write new applications
and port existing ones.
The 64-bit Windows platform will bring the following
benefits to the developers and end users:
- The full advantage of IA-64's reliable, high-
performance, and high-availability architecture.
- Compatibility with Windows 2000-based applications
and existing 32-bit applications.
- API-level compatibility between the Win64TM API
and the Win32® API.
- Scalability of virtual memory up to 16 terabytes
(TB).
- Interoperability with systems based on existing
32-bit architectures.
The ever-expanding data needs of business, academic,
engineering, and scientific organizations push the limits and the capabilities
of existing information technology platforms. Today, gigabytes, or even terabytes(TB),
of data need to be accessed in real-time by millions of users worldwide, and new
technology is needed to meet this demand.
The 64-bit Windows platform will provide a scalable,
high performance solution. Its architecture allows more efficient processing of
extremely large amounts of data, supporting up to 16 terabytes of memory.
With 64-bit Windows, applications can pre-load substantially more data into
virtual memory to enable rapid access by the IA-64 processor. This reduces the
time for loading data into virtual memory or seeking, reading, and writing to
data storage devices, thus making applications run faster and more efficiently.
The increased capabilities of computers based on 64-bit
Windows and the 64-bit Intel processor are compared with existing 32-bit
capabilities in Table 1 below.
Table 1: Comparison of 64-bit and 32-bit
Architectures |
Back to Top |
Architectural Component | 64-bit Windows 2000 | 32-bit Windows 2000 |
Virtual Memory | 16 TB | 4 GB |
Paging file size | 512 TB | 16 TB |
Hyperspace | 8 GB | 4 MB |
Paged pool | 128 GB | 470 MB |
Non-paged pool | 128 GB | 256 MB |
System cache | 1 TB | 1 GB |
System PTE | 128 GB | 660 MB |
Note: This documentation describes products still in development.
Products and features as described in this document are subject to change and
may change substantially before final commercial release.
Microsoft understands that technology managers and users
need to use existing investments in earlier versions of Windows. Within the
64-bit Windows product development programs, Microsoft is working with
third-party application developers to ensure that their software can run
unmodified on 64-bit Windows-based computers; this means that adding 64-bit
Windows-based systems to existing networks will not require changing the
applications you use.
As organizations begin deploying the 64-bit platform,
most applications that run on 64-bit Windows-based computers will need to be
ported from a 32-bit application platform in order to take full advantage of the
new benefits of the 64-bit platform. Microsoft supports the goal of porting
applications using the 64-bit Windows data model. This data model enables the
writing of single-source code that can run on both 32-bit and 64-bit computers.
The 64-bit Windows data model provides new pointers and
data types that developers can use to automatically size data. Essentially, in
this model, all of the integral data types used in Win32-based applications will
remain the same, while supporting new 64-bit pointers and data types. New data
types include fixed-precision data types, pointer-precision types, and
specific-precision pointers. This enables data associated with pointers to
change size when its associated pointer size changes from 32 bits to 64 bits.
However, because the underlying, integral data types remain 32 bits in length,
there is no change in size of data on disk, data shared over a network, or data
shared through memory-mapped files. This relieves developers of much of the
effort involved in porting 32-bit code to a 64-bit system.
Microsoft is committed to helping developers port
existing applications from a Win32-based environment or build entirely new
applications from the ground up. The Windows 2000 Software Developers Toolkit
(SDK) and Device Driver Toolkit (DDK) provide tools for the development of
single source-code for Win32- and Win64-based applications. Developers working
on Win64-based applications will find the environment virtually identical to the
environment for Win32-based applications; the Win64 API is the same as the Win32
API.
The 64-bit Windows development environment aims to
support the same feature set as 32-bit Windows, including user interface and
programming models, networking, security, graphics, multimedia, directory
service, Plug and Play, and tools features. Many of the functions have been
modified to reflect the computational precision of the platform on which an
application is run.
The result is simplicity and a short learning curve for
the developer—writing code for 64-bit Windows is just like writing code for
32-bit Windows. This means that developers can compile a single source base to
run natively on either Win32- or Win64-based systems. This strategy reduces the
cost of developing applications for the 64-bit architecture.
For more information on how to write new 64-bit
applications today, see Getting Ready for 64-bit Windows
See what leading trade magazines are saying about 64-bit
Windows:
- Intel, Microsoft Demo
64-bit Windows
ComputerWorld, Sept. 1, 1999.
- 64-bit Windows Booting, Running on Merced
Prototype
ENT Online, Aug. 31, 1999
- Microsoft: 64-bit Windows
Is On Track
Sm@rt Reseller, Aug. 31, 1999.
- Intel Demonstrates Merced
Computer Reseller News, Aug. 31, 1999
Microsoft Press Release
NEC Press Release: 16 Itanium Processor Based Prototype IA-64 Server
Intel Press Release: Itanium is New Brand Name for its First IA-64 Processor
Intel's IA-64 Developer Information
Platform SDK: Getting Ready for 64-bit Windows
Platform SDK: Designing 64-bit-Compatible Interfaces
|
 |
