intra-drive RAID?

[KingGheedora]

I have always wondered about this. Has anyone ever built a hard drive with say 2 platters, where the read/write heads are attached to the same arm such that the hard drive reads and writes to/from each platter simultaneously?

Basically as many platters as there are, that's how many bits can be read or written concurrently.

Is this possible? Why don't we see this for sale all over the place?

 

[jimhsu]

Hard drive with multiple acutators have been tried before, if that's what you mean: http://www.pcguide.com/ref/hdd/op/actMultiple-c.html

Other than that, the reason is probably economical; basically 2 hard drives with n platters each ends up cheaper per GB than 1 hard drive with 2n platters and 2 read heads, engineering and reliability wise.

As to your question of whether it will ever be practical, google HRD technology. 64 heads is far better than 2...