On 23 Aug 2004 at 14:41, Eric Dannewitz wrote: > You know, I read an article about comparing NTFS (windows file format) > and HFS+ (OS X format). . . .
Disk caching in Windows is not part of the file system. It's part of the I/O subsystem that sits on top of the file system (which could be NTFS, FAT32 or FAT16). > . . . Disk Caching is important, but there are other > things to consider as well. . . . Disk caching is absolutely essential to decent performance in Windows. > . . . Fragmentation is a big issue. . . . Not even close to being as important as disk caching, since it only matters on initial read of the file, and really only matters with large files. > . . . I know my > Windows XP machine has to get defragmented every couple of days, . . . ??? NTFS does basic background defragmenting (it doesn't rewrite the files into completely contiguous blocks, but does try to get the data pages into an order that is more efficient for the drive to read than the default assignment off the free chain). > . . . but > it is not an issue on OS X 10.3 due to the OS's built-in > defragmentation of files used often. If I find the article I'll post > it. It was techie but interesting on how caching and file systems > work. I hardly ever defrag any of the machines I'm responsible for, and it's never improved performance noticeably when I've done it. Why? Because defragging basically is only relevant for large files that are read often. And once read, they are cached in memory, so if the original file image is fragmented, it really doesn't matter once it's been read into memory. > Does this matter with temp files? Perhaps. . . . I don't think fragmentation matters for temp files. > . . . Is it likely that when you > are using Finale on Windows that it is keeping all the temp files in > memory? Probably not. . . . I disagree entirely. My bet is that all those files are in the disk cache, not being read/written from/to the disk each time (actually, an explicit save probably does a forced write to the original file, but changes in the temp files themselves are probably in the write- ahead cache, and reads are coming from the cache in most cases). > . . . I see my little hard drive light go on all the > time with Finale. . . . That doesn't mean anything. OS subsystems may be doing any number of things that cause disk reads/writes. > . . . I'm sure that there is some sort of Windows tool out > there that one can run if you really want to find out what is going on > in the cache. I stopped worrying about it a long time ago when it became clear to me that MS had engineered something the worked extremely well and so there was no need to try to tweak it any more. -- David W. Fenton http://www.bway.net/~dfenton David Fenton Associates http://www.bway.net/~dfassoc _______________________________________________ Finale mailing list [EMAIL PROTECTED] http://lists.shsu.edu/mailman/listinfo/finale
