There are some circumstances in which you will want to set up partitions that are
smaller in size than usual, or where you might want to dedicate a partition to a specific
use, or ensure that it occupies a particular place on the disk. Here are some of the extra
issues you may want to take into account when considering how to partition your disk(s):
- Partition Placement: Most hard disks use zoned bit recording, which means they
hold more data per track at the outermost edge of the disk than they do at the innermost
edge; as a result, the outer tracks tend to deliver better performance than the inner
tracks do. Since the outer tracks are used first, this means that the first partition on a
physical disk volume will be slightly faster than subsequent ones. If you have certain
files that require higher performance than others, placing them in a partition at the
beginning of the disk is preferred.
- Dedicated Partitions: Notwithstanding my long argument against splitting the disk
into many partitions where each is for one type of file, there are special situations
where it may make sense to dedicate a partition to one use. The most common case where a
partition is dedicated to a specific use is for the virtual memory swap file for a
multitasking operating system. This file is very important since it is used often for
certain types of heavy processing, and being able to control the exact properties and
location of the partition that it uses can be advantageous.
- Cluster Sizes for Special-Purpose Partitions: Again, having specific partitions
for certain types of files can cost you flexibility, but in some cases it can make sense.
If you are doing a lot of work with large multimedia files, you may want to intentionally
bump up the cluster size to a larger value. The main reason for this is that there is less
overhead when using larger clusters--doing a sequential read of a 10 MB file on a volume
that uses 32 KB clusters means 319 "next cluster" lookups in the FAT. Reading
this entire file on a volume with 2 KB clusters increases this to 5,119 lookups. Another
reason is that since every cluster is a contiguous block on the disk, having a larger
cluster size means a greater percentage of the file is in continuous blocks--less
fragmentation. This means better performance for long sequential accesses (but frequent
defragmentation of a disk with smaller clusters will mitigate this effect).
The three points above mean that the ideal place in many cases for the swap file under
Windows 95, for example, is in a dedicated partition at the start of the second disk in a
two-disk system, and this is what I use in my own personal PC. I have two disks that are
approximately the same size and speed, and the swap file takes up the entire contents of
the first partition of my second hard disk, which is about 63 MB in size. I used Partition
Magic to set this partition's cluster size to 32 KB, even though a partition of this size
would normally only use 2 KB clusters.
Next: Drive Letter Assignment and Choosing Primary vs. Logical Partitions
