HP Vectra XU 6/XXX HP Vectra XU 6/xxx, Guide to Optimizing performance - Page 24

1 Your PC's Performance Features Matching Memory Capacity to Your Requirements What Else is Memory Used For? Many operating systems use memory to accelerate data transfers with the PC's hard disks. To do this, an area of memory is dedicated to a disk cache, which stores copies of the latest data read from or written to the hard disks. If the processor then accesses the same data again, it will be loaded from memory at much higher speed than from hard disk. Because much of your PC's work is repetitive, disk caches offer a significant performance advantage with most applications. The amount of memory dedicated to the disk cache is determined by the operating system you are using. Data copied from the hard disk drive to the disk cache Hard disk drive Data accessed at the access speed of the hard disk drive (typically 10 mS) Memory dedicated to the disk cache Data accessed at the access speed of memory (60 nS) Some operating systems, such as Windows for Workgroups, allocate a fixed disk cache, which you can configure directly. Others, such as Windows NT and Windows 95, use a dynamic allocation mechanism that configures the disk cache according to the amount of memory available. The memory used by the disk cache will not be available for use by your applications. When determining your memory requirement, remember to add an extra allowance for the disk cache. 18 English