Disk Cache is a part of RAM that acts as an intermediate buffer when data is read from and written to storage devices.
The Disk Cache driver stores the most recently accessed data in RAM. When a program needs to access new data, the operating system first checks to see if the data is in the cache before reading it from the disk. Because computers can access data from RAM much faster than from a storage device, disk caching can significantly increase performance.
What's the problem with the Windows 9x-ME Disk Cache?
The Virtual Memory Manager and the Disk Cache driver are two separate entities. The Virtual Memory Manager decides what portions of physical RAM can be swapped out to Paging file, while the Disk Cache driver determines what portions of disk files in use should be kept in memory to avoid slow disk operations. Unfortunately, the left hand doesn't know what the right hand is doing. The Disk Cache driver decides to cache data in RAM while the Virtual Memory Manager decides to swap out memory back to hard drive. In some cases, the two defeat each other, resulting in extremely bad system performance.
Cacheman will help you set the Disk Cache driver limits for your system and if necessary gain more free memory.
If you are not an expert user, launch the wizard for automatic settings or use one of the predefined profiles.
How can I test if my system has optimal Disk Cache settings?
A benchmarking program is not suitable for this purpose. A large Disk Cache speeds up most IO operations and the re-loading of applications by a significant amount, but on the other side if no free RAM is left a too large Disk Cache can decrease the general application performance by a huge amount due to increased paging file swapping.
The best method to test your settings is to create a worst-case scenario by loading several applications at the same time and work with them. If you encounter major slow downs (e.g. by processing large images in graphic software) try to reduce the Disk Cache to gain more free RAM. Registered Cacheman users can contact support to get performance related help.
Chunk Size
The Disk Cache is a single block of memory which is divided into chunks. The performance changes slightly with the Chunk Size. If it is too small, the data must occupy too many chunks and vice versa. An optimum size must be arrived at so that the Chunk Size is not too large and not too small. The default size of 512 Bytes is best. Most Windows versions ignore this setting anyway, so leave it at default.
Name & Path Cache
Path Cache specifies the size of the cache that the virtual file allocation table (VFAT) can use to save the locations of the most recently accessed directory paths. Name Cache stores the locations of the most recently accessed file names. This cache improves performance by reducing the number of times the file system must seek paths by searching the file allocation table. The memory is allocated out of general system heap.
A Wizard is available for novice users.
CDFS Cache
The CDFS Cache is separated from the Disk Cache because the performance characteristics of compact discs are different. This cache can be moved to swap file. When Windows retrieves data from a compact disc, it is still faster to read a record from the CDFS Cache even if it has been swapped out, because the hard drive access time is much faster compared to access time of the CDRom drive. DVDs primarily use the Universal Disk Format (UDF) for their file systems, this means the Disk Cache is responsible for most DVD-Discs, not the CDFS Cache!
A Wizard is available for novice users.
Icon Cache
Every executable file has an icon associated with it. Every time the shell displays a folder full of files it needs to obtain icons for each of those items. By saving icons that it has already retrieved into a cache, the shell is relieved of the need to constantly retrieve icons from executable files and icon libraries. This can make a vast difference to system performance, especially when accessing network drives.
After changing this setting you need to reboot at least 2 times until it becomes effective, but since it's not a critical setting Cacheman will not ask you on exit to reboot.