· : ¦ . _________ ________ _____________ ._____¦ | · __ / : ___________/ _ \ \ __ _ / | \ |____: : \_/ -A : \______ \ | \_ _: \_/ \_/ | \ ¦ | ¦ \_ ··D_ / / _/ | / |___/ \_ | : : | |_______/ `N· _/ \ \_________/ | \________/ ¦ |_____¦ ¦ | : \__________/ \ ¦ \_ : : \__________| \___________/ . · . »»»» PRESENTS «««« HYPERCACHE ========== TYPED BY SHARD HISTORY ------- NEW SUMMARY VERSION 1.01C The new version of Summary included on this diskette cures an infrequent problem with some systems which caused Summary to not locate all active caches. CHANGES FOR VERSION 1.01B The diskchange logic code has been replaced, enabling more effective determination of disk changes, particularly on removable media where more than one filesystem is being run on that device (eg: DF0 with both AmigaDOS and an MSDOS filesystem active) The device search routine has been revised, eliminating infrequent enforcer hits that may have occurred on some systems in earlier versions. The cache is approximately 25% faster than the initial 1.01 release. CHANGES FOR VERSION 1.01 Version 1.01 is approximately 35% faster than version 1.0 HINTS, CAVEATS What do "lines", "sets", and "prefetch" mean? A set is a completely independant cache for your device. Rather than running only one cache when you start HyperCache, it sets up several, as defined by the value of your "sets" parameter, or 8 by default. In this way, if a sector cannot be found in one cache, it may be found in another. Although transparent to you, it increases the chance a sector will be found in the cache (known as your "Hit Ratio"). The amount of "prefetch", which defaults to 4 sectors, refers to the size of the sector groups which HyperCache moves to and from the actual device. If prefetch is 4, for example, HyperCache will never read less than 4 sectors at a time from the device. Not only is it more efficient to read several sectors at once, but it can also increase your performance, since when your application wants the next sectors from the device, they are often already in memory, even before they are needed! The number of "lines" refers to the number of these prefetch sector groups per "set". Thus, at default, you have 8 sets each with 32 lines of 4 sectors each. The overall size of the cache can thus be computed as LINES * SETS * PREFETCH * 512. (Here 512 is the number of bytes per sector). Changing the cache size: The default cache geometry is 4 prefetch, 8 sets, and 32 lines. If you wish to double the size of the cache, you can double any one of these parameters. It is generall suggested that you double the number of lines or sets, rather than prefetch. For example, to set up a one megabyte cache on DH0:, you would enter the following: HyperCache -v dh0 -l 64 // Recommended for 68000 systems or HyperCache -v dh0 -s 16 // Recommended for accelerated systems The number of "sets" is actually the number of independant caches that will be set up for that device, and "lines" is the size of each one of those caches. Increasing the number of sets normally increases the cache hit ratio, but requires slightly more CPU to locate a sector in the cache. For slow media or fast processors, this is recommended as the setting to increase. For a standard 68000 CPU with a fast hard drive, we recommend increasing the number of lines instead. The -p parameter allows you to specify the minimum number of sectors that will be read from the device, regardless of how few an application actually requests. Under normal circumstances, this can increase performance significantly. On a very fragmented drive, however, it can actually hurt performance. If this is the case, it is suggested you defragment your hard drive or decrease the prefetch to 2: HyperCache -v dh0 -p 2 -s 32 [ Note that you may supply any one, two, or three of the -s, -l, and -p options. Those that are not supplied will retain their default values. ] You may wish to experiment with these values to determine which provides the best results for your particular system and usage. If you are having trouble getting HyperCache to detach from the command line, ie: you cannot close the Shell or CLI window from which it was run, remember to include the -n parameter on the command line. This prevents HyperCache from displaying its startup information and locking the output stream for that window. When using a backup program and writing to a floppy disk, you should disable caching on that floppy if you intend to verify your writes. If you fail to do this, the backup program will verify what it has just written against what was retained in the cache, which is pointless. You need only do this for the drive you are writing to. HyperCache may be left active on all other devices. It is recommended that you disable HyperCache on any drive which you may be performing low-level repairs to, such as a disk salvage operation, DiskDoctor, or a file re-orginization process. HyperCache will not normally interfere with these operations, and has never shown to be incompatible with them, but it is still an advisable safety precaution. Users of 68020-based systems may opt to use the special 68030 version of HyperCache included in this distribution, although the code itself has been optimized with the 68030 processor in mind. Some users have experienced problems when starting Consultron's CrossPC after starting HyperCache. If you experience such problems, try starting HyperCache after CrossPC. This only effects drives which CrossPC will share with AmigaDOS. If you are not receiving as big a performance jump as you had expected, you may want to check your hard drive for fragmentation. Fragmentation (which means large files are broken up into smaller pieces and scattered across the disk) hurts the performance of HyperCache significantly. To defragment your drive, you may use any of several available commercial and shareware hard drive reorganizers. Backing up your drive, formatting it, and restoring it will have the same effect, but of course takes more time. Problems with Certain Devices and Controllers: Some users have reported problems with the HardFrame controller as well as certain ICD controllers. If you have such a controller, and have been experiencing problems with it, please indicate this on your registration card. We are continually revising the product to enhance its compatibility with non-standard controllers, and may have a fix for you. HyperCache has been optimized for use with the OFS, FFS, and MSDOS filesystems, all of which employ a 512 byte sector size. If you are using a device which deviates from the 512 byte normal, please contact us, as we can provide a version which is far more generic in its approach to the filesystem (although at a slight cost in performance). Please note that for the protection of the customer and the authors, all executables on this distribution disk are serialized and traceable. If you are impressed enough to consider giving a copy of your HyperCache to a friend, don't! :-) All product names are trademarks of their respective owners. ------------------------------------END-------------------------------------------