Comments on a very occasional diary: A voice of the reason from the distant past

High-end IBM installations use "fixed-head disk...

2006-08-21T15:52:00.000Z
High-end IBM installations use "fixed-head disks", where each track has its own head.

Well, this sound almost like the good old drum. And no, I really don't want to imagine the price of such a beast. ;-)

I was actually thinking of just sticking an arm into each corner of the case of your average disk: four arms, quarter the average seek time, and up to four times the throughput (yeah, I know this is a misleadingly coarse upper bound). And it doesn't seem to be that much more arms and heads to make it cost insanely more. Though, frankly, I have no idea what are the expensive parts of a disk, and making a firmware to use those four arms really well may also be a bit tricky.

-- crankyjack

I wonder why disks don't have more than one "mo...

2006-08-21T15:18:00.000Z
I wonder why disks don't have more than one "moving arm"
In fact, some of them do. High-end IBM installations use "fixed-head disks", where each track has its own head. You may imaging the cost of it.

I wonder why disks don't have more than one "movin...

2006-08-21T15:10:00.000Z
I wonder why disks don't have more than one "moving arm". With native command queue SATA disks (and something similar surely existing in the SCSI world for a long time), you could get quite an improvement in seek time and throughput... Or not actually?

Good luck finding a drum storage unit these days ;...

2006-07-23T21:09:00.000Z
Good luck finding a drum storage unit these days ;-)