Calculating Hard Disk Size

[n0namebrand]

I have a Seagate 320GB SATA-300 internal hard drive, model TSD-320AS. The logical geometry of the hard drive is 16,383 cylinders, 16 heads and 63 sectors per track.

To my knowledge,

Capacity = Number of cylinders × number of heads × sectors/track × 512 = hard disk size (bytes)

For my specific hard disk my calculations are:

16,383 * 16 * 63 * 512 = 8455200768 bytes (not close to being right)

Does anybody know where I'm going wrong here?

[oz]

Welcome to the forums!

Here's a media size calculator you can use if that helps:

Media Size Calculator

[n0namebrand]

Thanks for the welcome and the media calculator!

I noticed this on the media calculator page:

WD Caviar AC28400 Drive H=16, C=16383, S=63, B=512, Size=8.4GB

The 8.4GB WD Caviar has the exact same cylinders, as my 320GB Seagate. I guess my cylinder values are wrong...

MaxtorDiamondMax D540 Drive H=16, C=317632, S=63, B=512, Size=160GB

The 160GB Maxtor is exactly half of my 320GB Seagate. The 160GB Maxtor's cylinders are 317632.

317632 * 2 should give me my Seagate's cylinders, correct?

[oz]

I looked up the specs on your drive and it appears that you are correct about them in your first post.

[n0namebrand]

Thanks ozar, I've been searching google too for my drive's specs and all I find is 16,383 cylinders. That would make my 320GB capacity ~8.4GB...according to these calculations 16,383 * 16 * 63 * 512 = 8 455 200 768 bytes. I'm really scratching my head here.