AutoCADder

Many people believe that Windows Vista makes more RAM available for your CAD programs. But if you compare the most common versions of Windows XP and Windows Vista, nothing has changed in terms of memory limits. The 32-bit version of Windows XP and Vista 32-bit share the same application memory limit of 2GB (or 3GB in special modes).

If you need more memory - what you always need when working with large CAD data - you have to pick the 64-bit version of Windows. But again, the 64-bit version of Windows XP and Vista 64-bit share similar memory options. Even in the 64-bit OS a 32-bit application cannot use more than 4GB of RAM; native 64-bit applications can use virtually unlimited memory. So remember - Vista doesn't bring higher memory limits, the 64-bit operating system does.

There is one more difference between WinXP and Vista - the way you control the 3GB memory mode. If your 32-bit application supports this mode (e.g. AutoCAD, Inventor, Revit, Civil3D...), this mode makes 3GB of RAM available for it. In Windows XP, this mode is switched on through the BOOT.INI config file (/3GB). In Windows Vista, you can switch this mode with the BCDEDIT config tool - as described here (bcdedit, not bsdedit) or here.

Labels: 32-bit, 3GB, 64-bit, AutoCAD, RAM, Vista