If you know the disk capacity, bytes per track, and number of surfaces, then how do you calculate the number of tracks?
Number of tracks
hard drive
Related Solutions
Almost all modern hard drives report 63 sectors per track, because that's the maximum allowed by the BIOS specs.
This number (along with heads and cylinders) is of course fake and used only for compatibility addressing with very old programs. Internally they use a simple sector number starting from 0 (called LBA mode).
The real sector per track number is not only much larger, but it also varies depending on the distance from the spindle. See, for example, this page from the makers of HDDScan.
Bytes per track depends totally on how the manufacturer laid out the disk internally, which you will not know. All modern disks use LBA (logical block addressing), in which the OS addresses the drive on a sector-by-sector basis, not knowing or caring how or where the sectors are physically located on the platters (nor how many platters there actually are).
Not only that, but the number of sectors per track depends on how far out from the spindle motor you are at the time; it's not a spiral like on a CD. The further from the spindle you are, the more sectors per track (and thus the higher the transfer rate).
The following diagram explains it, but note that the diagram is partially incorrect -- instead of the sectors getting bigger as you go outwards from the spindle, the sectors remain the same size and there are more of them per track the further from the spindle you go (which causes your number of bytes per track, sectors per track, etc to go up).
Since the heads will be over a certain track for only one revolution, and you don't know where on disk you are, you cannot know if the next track will have more or fewer sectors, and therefore your transfer rate will fluctuate.
That said, it will only fluctuate if you are reading directly from disk and not out of cache; modern drives have advanced caching algorithms which will prefetch content it thinks you'll ask for next. As a result, if you were measuring transfer rate, you have no idea if it's coming off the platters or out of cache, making such measurements unrepeatable and totally useless.
In other words, you don't. Period.
Best Answer
Number of tracks is totally dependant on how the manufacturer laid out the disk internally, which you will not know. All modern disks use LBA (logical block addressing), in which the OS addresses the drive on a sector-by-sector basis, not knowing or caring how or where the sectors are physically located on the platters (nor how many platters there actually are).
Not only that, but the number of sectors per track depends on how far out from the spindle motor you are at the time; it's not a spiral like on a CD. The further from the spindle you are, the more sectors per track (and thus the higher the transfer rate).
Since you do not know the number of sectors per track (which, again, varies depending where on disk you are), you cannot determine how many tracks exist, given capacity, number of sectors, and number of surfaces.
In other words, you don't. Period.
UPDATE:
If your teacher wants a mathematically correct answer, it would be (CAPACITY_IN_BYTES / BYTES_PER_TRACK) to get the number of tracks on disk, and if you want tracks per surface, divide the number of tracks on disk by the number of surfaces.
However, note that this is totally inapplicable to modern drives. The real answer is that it cannot be calculated since you do not know how many sectors per track there are (and there are a variable number in different zones of the disk) -- hence, there are too many unknowns to be able to solve the formula.