Filesystem v. partition

the_bro

In lesson 17, the section on "Why Partition" introduces 6 reasons, namely:

1. Separation of user and application data from operating system files
2. Sharing between operating systems and/or machines
3. Security enhancement by imposing different quotas and permissions for different system parts
4. Size concerns; keeping variable and volatile storage isolated from stable
5. Performance enhancement of putting most frequently used data on faster storage media
6. Swap space can be isolated from data and also used for hibernation storage

I'm wondering whether Performance enhancement (#5) belongs, since this surely is a function of a filesystem on different media.
For example, if I have 2 disks, one's a SSD and the other a traditional HDD, I could see the value of partitioning for #s 1-4,6 on the disk, but it wouldn't help much in terms of performance if I place data in its own partition -- I would have to create a filesystem on my SSD for that.
In other words I shouldn't expect any partition on a disk to offer me increased performance over any other on the same disk, should I?

coop

On rotational media it has always been believed that access times are faster towards the center of the disk, since the radial divisions get wider as you towards the outer surface, and measurements indeed showed this. SO the idea was to put frequently accessed data near the beginning of the disk. I don't know how true this is anymore with rotational disks which have gotten more complicated and do a lot of geometry faking now. However, as you are noting, for an SSD none of this matters as not only are all parts of the disk equally accessible, you actual want to spread the data out over time to minimize the number of read/write cycles any block has -- you want "load-leveling"

If you are considering different kinds of media then you still want to put partitions perhaps on SSDs and modern very fast SSDs to optimize, but indeed all partitions on the same physical device should be equal pretty much.