OC a hard drive?

[calgar]

i remember reading in a oldish computer book that hard drives have a platter that is used for data only if a bad block is detected on the hard drive, but you could (somhow) do somthing to allow that space to be used like ordinary, is this true? if so how? and is it worth it nowadays?

[GrahamGarside]

Well a lot of hard drives have unused space because they are a size which doesn't fit exactly into the size of the platters. For instance a Seagate 7200.7 has a platter size of 80GB, so the 80GB and 160GB drives fit nicely. The 120GB and 200GB drives have 40GB left unused. Now I don't know if manufacturers do like GPU makers do and use partially faulty units and only use the usable section (like a 6800 may have 4 damaged pipelines so only 12 are used) or not but I have never heard of anyone being able to reclaim that space.

[Áedán]

I'm not aware of drives reserving a platter - that would be fairly expensive to do these days, and would kill market share. However, there are some areas where sectors are held spare, so the drive can reallocate a damaged sector to one of these spare sectors.

Typically there aren't that many that it's worth trying to 'unlock' them, and it might require firmware adjustments to the hard disk.

Some drives of 'inbetween' storage space simply don't use one side of a platter. In Graham's example, a 120GB drive is lacking a physical head to read one side of a platter, so it's not possible to use that side.

In theory, it'd also be possible to actually overclock a hard disk, but I'm not sure what the tolerences really are. The limiting factor is the frequency response of the heads on the hard disk, and the filtering applied to their signal to shape it.

[GrahamGarside]

Of course if it's a shop bought or oem built system there may be about 3gigs of space hidden for recovery on the drive
Again I don't know how to recover this

[Áedán]

Typically it's just a partition on the drive. Deleting the partition table would do that. Of course, for some systems, that means you can no longer access any of the system utilities, and may also invalidate the warrenty on the system!