Quick & Dumb Hard Drive Question (1 Viewer)

[JasenP]

Are larger drives slower than smaller drives?

If two drives have EXACTLY the same specs (ATA133, 7200rpm etc..) except for the size (80gb vs 120gb) is the 120gb going to seek or write slower?

 

[Rob Gillespie]

Usually it will be just the opposite, if the drives are otherwise identical. The larger drive will often have a higher packing density, giving it a very slight edge in performance. This is certainly the case with Seagate's current Barracuda IV range and I'd imagine is also applicable to other manufacturers.

Of course, that only applies when the drives are from the same range, from the same company. When you're comparing an 80gb Seagate and a 120gb IBM there's a lot of other variables brought into play.

 

[Dustin B]

Are you sure about the packing density Ron. I always understood it that within the same models drives went up in size by the amount of data that can be stored on a platter. So most drives currently use 20gig platters. Which is why we see 20, 40, 60, and 80 gig drives (1, 2, 3, and 4 platters respectively).

Although I guess to get to the 100gig plus drives the plater density needs to go up since I don't think they can fit more than 4 or 5 platers in a drive.

 

[Rob Gillespie]

It depends on the model/manufacturer. I remember reading the reviews on StorageReview.com when I was considering replacing my IBM 75GXPs for Seagate Barracuda IVs (which I did and am very happy with). The 80gb model recorded faster access and throughput than the 20gb model.

That said, we're talking tiny differences here. I doubt if you'd actually notice the difference during normal use. You're more likely to notice the decrease in speed from a single drive as it goes from outside tracks in.

 

[Kevin P]

All else being equal, a 80 GB drive with 20 GB of data will be faster than a 20 GB drive with 20 GB of data. That's because the data is packed more closely in the 80 GB drive, reducing the distance the heads have to move to access the data.

The main factors in a drive's performance speed are the RPM (the faster the disk spins the lower the latency, that is, the amount of time for a given piece of data to "spin" under the head); the seek time (the average time for the heads to move from one part of the disk to another and then stop and be able to read or write data), and the transfer speed, which is a function of the RPM and track density. And of course, the bus speed plays a role too, which would make a UDMA 133 drive faster than a 100 all else being equal, as it can truck the bits from the drive to the CPU faster.