Vista SP1 Installed System Memory (RAM)

One of the aspects that Service Pack 1 changes for Windows Vista is the way that the operating system reports the amount of installed system memory. The way that Vista SP1 now deals with the physical RAM impacts both the 32-bit and 64-bit versions of the platform and end users could experience an increase of the memory value reported. According to Microsoft, in the eventuality that physical memory was reserved for the graphics card, or if additional peripherals share the RAM via settings in the system BIOS, and also on computers with more than 3 GB of system memory, Vista SP1 will report the full resources available.

"This change occurs because Windows Vista with SP1 reports how much physical memory installed on your computer. All versions of Windows NT-based operating systems before Windows Vista Service SP1 report how much memory available to the operating system. This change in Windows Vista SP1 is a reporting change only," Microsoft informed.

Vista SP1 end users will be able to notice the increase in RAM reporting across various areas of the platform including the Welcome Center, in My Computer windows, System Properties windows as well as into the Performance Information and Tools item in Control Panel. RAM reporting evolved in Vista SP1 to include Installed Physical Memory (RAM), Total Physical Memory and Available Physical Memory in the System Information tool.

It is important to understand that not all the physical RAM is available to the operating system. Before SP1, Vista only took into account the system memory that it could use, and ignored the rest, even if it was installed. Because of BIOS and driver reservations of RAM, both 32-bit and 64-bit editions of Vista RTM failed to report the full amount of memory on a system. Vista SP1 comes to resolve this problem, and will provide correct information of the hardware configuration even if the operating system has to share the RAM and can use only a portion of it.

"On computers that have a 32-bit operating system, more than 3 GB of system memory, and with a version of Windows that is earlier than Windows Vista SP1, users will see a larger difference in how much memory is reported as available to the operating system compared to how much physical memory is installed. This is because some physical address space must be reserved as I/O regions for memory mapped peripherals. These I/O regions are allocated between the 3 GB physical address and the 4 GB upper physical address limit," Microsoft added.

Source: news.softpedia.com