How many bytes are in a memory page?
A memory page is the minimum unit of memory allocation in OpenVMS. With OpenVMS VAX, the memory page size matches the disk block size: it is always 512 bytes. With OpenVMS Alpha, the memory page size is variable, and it can range from 8192 bytes (8 kilobytes) up to 64 kilobytes. The current system page size can be determined using the sys$getsyi or f$getsyi PAGE_SIZE item. Programs with hardcoded constants for the memory page size (or page alignment) should always assume a page size of 64 kilobytes. On OpenVMS I64, the memory page size is also variable, ranging from 4096 bytes (4 kilobytes) up to 256 megabytes (MB) and potentially up to 4 gigabytes (GB). As with OpenVMS Alpha, sys$getsyi and f$getsyi and the PAGE_SIZE itemcode can and should be used to determine the current system page size. In general, OpenVMS I64 will use a page size of 8 kilobytes, or larger. On OpenVMS Alpha and on OpenVMS I64, a 512 byte area of memory- equivalent in size to an OpenVMS VAX memory page-is often ref
A memory page is the minimum unit of memory allocation in OpenVMS. With OpenVMS VAX, the memory page size matches the disk block size: it is always 512 bytes. With OpenVMS Alpha, the memory page size is variable, and it can range from 8192 bytes (8 kilobytes) up to 64 kilobytes. The current system page size can be determined using the sys$getsyi or f$getsyi PAGE_SIZE item. Programs with hardcoded constants for the memory page size (or page alignment) should always assume a page size of 64 kilobytes. On OpenVMS I64, the memory page size is also variable, ranging from 4096 bytes (4 kilobytes) up to 256 megabytes (MB) and potentially up to 4 gigabytes (GB). As with OpenVMS Alpha, sys$getsyi and f$getsyi and the PAGE_SIZE itemcode can and should be used to determine the current system page size. In general, OpenVMS I64 will use a page size of 8 kilobytes, or larger. On OpenVMS Alpha and on OpenVMS I64, a 512 byte area of memory— equivalent in size to an OpenVMS VAX memory page—is often
