HDD Thickness!

[ithehappy]

Well I got back my old Hitachi 160 GB HDD as a replacement. When inserting I noticed a huge difference in thickness compared with my new Seagate 500GB SATA. The Hitachi's thickness is double of the Seagate's. Both are of 7200 rpm's. May I know why there is a big difference in thickness?
Attaching a pic.

*img573.imageshack.us/img573/7559/photo0067x.th.jpg

Uploaded with ImageShack.us

 

[Tenida]

My old seagate 40Gb (2001 version) is also thick like yours.

 

[coderunknown]

maybe Hitachi using 4-5 platters. Seagate using 1 or maybe 2.

 

[ithehappy]

So what's the effect of extra platters? Any differences in in terms of quality or performance?

 

[Tenida]

With single platter you get more performance vs 4-5 platters

 

[coderunknown]

^^ shouldn't be difference in performance. main difference are: eats more power (slightly more), makes more noise & gets warm (the one with more platter). non of them will cause any problem but a small drawback.