sub mesa :
So if people are trying desperately to use 6 partitions one for each purpose thinking it would have been faster. Even it it were; it probably wouldn't be enough to warrant investing so much time and trouble in an inflexible setup.
The number of partitions is solely personal choice. I just used 6 to make a case at the far end of the spectrum. Each user should pick what works best for them. Only unfamiliarity makes it unflexible. Takes about two minutes to change partition sizes. But by far the main reason people do partition is organization AND convenience. A single giant space does notjhing for organization and maintenance.
As an analogy I might ask would it be more convenient to store all your clothes all in one big drawer ? Or will you find things faster if you organize them ? Here's some other convenience issues to consider.
Do you want to schedule a 2 TB partition to defrag during your lunch break ? Or do you have a better chance of getting it done in 500 GB chunks ?
Backup is probably the biggest organizational factor. Is there any reason to backup your programs daily ? Seems like a lot of network traffic and / or tape wear and tear. So isn't a better choice to back up the Data partition daily, and the programs partition say monthly or after a new install / update ? Making image backups, these get made 'by partition".
Get your OS fudged ? What takes longer and is more effort .... reformatting your entire drive and reinstalling all your data ? With a small OS partition you can use your imaging program to restore C, more than likely, no problem with anything on the other partitions ... even if that isn't so, restoring from ya backups in windows is a lot easier than boot disk based solutions.
Dual booting is far more useful when you can isolate that 2nd OS on it's own partition. Have a family PC ? Nice to have your OS, programs and / or data on a partition that the kiddies have no access to. Have small office network and wanna share files ? Do you pick series of files and folders on each box or just give access to different classes of users by partition ? On an NAS this is normally done by allowing access to users by "volumes".
Yes, the concept does take some initial thought and planning and you are bound to make some wrong assumptions when doing it for the 1st time. But making partitions is no more complicated than buying those three ring punched sheets with the colored tabs for your school notebooks that kept you from mixing up your social studies notes w/ your math homework.