which is better in H.D : low number of platter or higher ?

[Hossam]

Hello ,

u can find in the market now 120GB & 180GB HD , so it may use 60 or 40 Platter ...

which is better ?


thanks in advance

 

[Lord Evermore]

Fewer platters means less heat and less power needed. If you compare two drives that have the same capacity (GB), then the one with fewer platters will have a higher density, which generally means higher performance (the heads have to move less to cover the same amount of data) as long as the rotation rate is the same.

 

[stonecold3169]

right... the bigger the platter size, roughly the better data throughput throught the platter. When the platter reaches it's edge, transfers slow, until it reaches the new platter. Therefor, the fewer platters you have, and the bigger they are, you might get a bit of extra performance from it

 

[Lord Evermore]

Actually, hard drives don't work by filling up one platter then switching to another. http://www.stevesdomain.net/articles.php?s=go&link=hdd The drive fills each cylinder first (each circular track around the drive on every platter), then moves inward to the next one. That's why if you use a program like HDTach that graphs the throughput, it's so jagged. It's from the heads moving inward in jumps. All the data being written to one cylinder gets about the same throughput.

The reason drives slow down near the "full" point is because they move inward, and on a circular platter, the inner tracks have less data passing under the head than the outer tracks in one full turn.

Storage Review also has a review of the new Barracuda ATA V drive from Seagate, which points out that higher density isn't an automatic increase in performance. They increased the number of tracks on the platter, but didn't increase the linear density of the tracks, so the same amount of data is passing under the heads. Performance on the inner tracks was actually worse than the ATA IV drive. But for the most part, you can assume that higher density means higher performance, and fewer platters has other advantages to make it worthwhile. Naturally of course, you can read reviews about drives to see if they have some drastic performance loss.