Paul Adams is, as ever, very right.
The idea of partitioning IS a good idea, but it's better with several small drives.
Picture this: a record player... very old.. it's got a record on it, and as with all record players, it has an "arm" with a needle upon it to run on the record and extract the sound.
Your favourite track in the first track... result... it's on the outter edge and it's where the needle falls autopmatically.
But your second favourite track is on the inner part of the album...near the centre spindle. To get to play it, you need to lift the arm and move it to the centre.. not a problem though, you know exactly where the track is
Now imagine you can also record a track to your record.. in fact.. you HAVE to record tracks to your record for it to work next time. And you have to move the needle to the right place to so. The problem is... the arm of the record player CANT be in both places at once. It HAS to swing back and forth, to the inner tracks, the centre tracks and the outer tracks...
it's busy... very busy,.
Imagine you had TWO record players... the favourite track is in the outer edge, of one and your newly saved tracks go on the outer edge of the other... concurrently/ at the same time.
Then, you'd be able to switch to your second favourite track while the other record was recording....
In essence, a hard drive has to do this is it's a traditional patter based drive. It can NOT do more than one partition at a a time. OK, in a hard drive they record and read at the same spot if ned be, and on the underside, but the PARTITIONS work like the rings of a cut through tree trunk... circular from the outside.
By all means have several, but don't expect the read/write head to be in two places at once