The modeling of jet engines with hundreds of sculpted parts will be a job for 64-bit CAD systems.

The modeling of jet engines with hundreds of sculpted parts will be a job for 64-bit CAD systems.

The latest computer operating system from Microsoft ( will let analysts build models comprising up to 16 Tbytes and that occupy a virtual address space of 8 Tbytes. Current 32-bit systems can address 4 Gbytes and have a virtual address space of about 2 Gbytes. The company says 32-bit and 64-bit applications can run on the same PC. CAD and FEA users will be among the first to benefit from the new OS because of its capacity for larger models.

But don't head down to the local Best Buy just yet. Windows XP Professional x64 Edition will be sold only on new computers through OEMs such as Dell and HP. There will be no retail version. A Technology Advancement Program, however, will let users exchange their 32-bit OS installed on computers equipped with 64-bit processors from AMD or Intel. "But it won't be a simple upgrade," says Jay Kenny, a Microsoft spokesperson. "It will require a wipe and reload."

"The OS is built from the Server 2003 code base to ensure reliability," he adds. Other features include a Windows Firewall and support for wireless operations, Bluetooth in particular. For security, Kenny says the OS sports XP SP2 improvements, stronger security setting and tools, and safer browsing and e-mail. Initial CAD offerings will come from PTC Inc. in Pro/E and UGS in NX. The initial rollout will be in English and Japanese and later in German, Chinese, and other languages.

The new OS also says goodbye to support for DOS, 16-bit applications, Posix, some legacy networking protocols, and 32-bit device drivers. Most 32-bit applications will operate well on the new OS with a few exceptions, according to Kenny. For one, 32-bit processes cannot load 64-bit ones and vice versa. And the only support for 16-bit code will be for some 16-bit installers. All kernel mode drivers must be 64-bit.

Nevertheless, Microsoft promises native execution of 32-bit programs on the 64-bit machine without the overhead of emulation. "In fact, some 32-bit programs may execute faster because of the additional resources," says Kenny. A third party expects to test for a benchmark figure available soon. The OS will cost the same as XP Pro 32-bit version.

How Memory and CPU Limits Compare

General memory limits
Totalvirtual address space (Gbytes)
Virtual address space/32-bit process (Gbytes)
2 and 3
2 and 4
Virtual address space/64-bit process
Not applicable
8 Terabytes
Paged pool
470/650 Mbytes

128 Gbytes

Nonpages pool
256 Mbytes
128 Gbytes
System cache
1 Gbytes
1 Terabytes
Physical memory and CPU limits (Win XP Pro)
4 Gbytes for 1 to 2 CPUs
128 Gbytes for 1 to 2 CPUs

The table compares memory and CPU limits for 32 and 64-bit operating systems.