Specifications

Computer Architecture and Maintenance (G-Scheme-2014)

instructions; a BIOS update is also needed. Newer multicore processors with 64-bit

support include these instructions as well.

The physical memory limits for Windows XP and later are shown in the table below:

Windows Version Memory Limit

8 Enterprise/Professional 512 GB

8 128 GB

7 Profession/Ultimate/Enterprise 192 GB

Vista Business/Ultimate/Enterprise 128 GB

Vista/7 Home Premium 16 GB

Vista/7 Home Basic 8 GB

XP Professional 128 GB

XP Home 4 GB

The major difference between 32-bit and 64-bit Windows is memory support—

specifically, breaking the 4 GB barrier found in 32-bit Windows systems. 32-bit versions

of Windows support up to 4 GB of physical memory, with up to 2 GB of dedicated

memory per process. 64-bit versions of Windows support up to 512 GB of physical

memory, with up to 4 GB for each 32-bit process and up to 8 TB for each 64-bit process.

Support for more memory means applications can preload more data into memory,

which the processor can access much more quickly.

64-bit Windows runs 32-bit Windows applications with no problems, but it does

not run 16-bit Windows, DOS applications, or any other programs that run in virtual

real mode. Drivers are another big problem. 32-bit processes cannot load 64-bit

dynamic link libraries (DLLs), and 64-bit processes cannot load 32-bit DLLs. This

essentially means that, for all the devices you have connected to your system, you need

both 32-bit and 64-bit drivers for them to work. Acquiring 64-bit drivers for older

devices or devices that are no longer supported can be difficult or impossible. Before

installing a 64-bit version of Windows, be sure to check with the vendors of your

internal and add-on hardware for 64-bit drivers.

Although vendors have ramped up their development of 64-bit software and

drivers, you should still keep all the memory size, software, and driver issues in mind

when considering the transition from 32-bit to 64-bit technology. The transition from

Prepared By – Prof. Manoj.kavedia (9860174297 – 9324258878 ) (www.kavediasir.yolasite.com)