The InRoads Group XM Edition will take advantage of the /3GB switch. This switch forces x86-based systems to allocate 3 GB of virtual address space to programs and 1 GB to the kernel and to executive components. With this switch, user mode programs can access 3 GB of memory instead of the usual 2 GB that Windows allocates to user mode programs. The switch moves the starting point of kernel memory to 3 GB1. The /3GB switch is added to the boot.ini file.
If you experience problems with the computer booting up (for instance, you are getting a blue screen on startup), then a second switch, "/Userva=2900", needs to be added. This boot option should be placed below the last successful boot option in the boot.ini file.
The lines in the boot.ini should look like this. multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional- 3GB" /noexecute=optin /fastdetect /3GB /Userva=2900
In tests, the /3GB switch approximately doubled the amount of points that could be read into the InRoads Group XM Edition (v8.9) and then triangulated. Depending on the system, the switch could increase the amount of points that can be created and then opened in the InRoads Group from around 7 million to 13 million.
Just because millions of points can be loaded into a model does not mean that doing so is the best workflow by any means. The user should be cognizant that the usage of huge files could impose a burden that can harm productivity. One good thing about the InRoads Group is that it processes profiles and cross sections very quickly even with the monster DTM. It is not recommended to dump all surface information into one file when dealing with extremely large amounts of surface data.
Warning: It is unknown whether or not the /3GB switch affects the behavior or performance of other software packages installed onto the computer.
1 "Available switch options for the Windows XP and the Windows Server 2003 Boot.ini files", Microsoft Corporation, 16 July 2008, http://support.microsoft.com/kb/833721/.