From: Todd A. Johnson (tajohnson@UCSD.Edu)
Date: Mon Mar 02 1998 - 16:17:50 EST
Dave- Everybody's getting close, but the easy answer can be found on Apple's TechInfo website (www.info.apple.com). TechInfo Article #8647 gives a good breakdown of what's going on. Notwithstanding any real compression schemes, the difference in file size between a 640 Mb MO cartridge, a 2Gb harddrive, and a 100Mb ZIP cartridge is purely based on the fact that under the Macintosh Hierarchical File System(HFS) and DOS a volume can only be broken down into 65,536 allocation blocks. The smallest file size cannot be smaller than the allocation block size. This is based on the 16-bit addressing that both the HFS and DOS formats use. You can see from this that a 640Mb Mo cartridge's smallest file size would be about 10Kb while a 2Gb hardrive partition's smallest file size would be 32Kb and a 100Mb ZIP disk's about 2Kb. All this means is that if you want to store just 1 character (basically 0.001Kb of information) your actually going to be taking up over 1000times that much space on your media. One way to get around this problem is to partition your harddrive into smaller pieces (logical volumes). Using Apple's HDSetup or a utility like FWB HD Toolkit, you can make your computer see the harddrive as several smaller units. The smallest file size is proportional to your partition size, not the total harddrive's. Also, Apple's System 8.1 now has an option for HFS+(extended format). This decreases the size of the allocation blocks substantially. I'm not sure that this partitioning scheme is meant to be used on removable media, so be careful. I hope this helps... Todd A. Johnson Kipps Lab Manager UCSD, Hem/Onc Division Webmaster University of California, San Diego School of Medicine La Jolla, CA 92093-0663 Phone: 619-534-5498 Fax: 619-534-5620 email:tajohnson@ucsd.edu WWW: http://orpheus.ucsd.edu/hemonc/HemOncHomePage.html
This archive was generated by hypermail 2.1.6 : Thu Jan 01 2004 - 17:35:14 EST
