Just bought this 1.5TB drive. I have a question.

[OCNewbie]

Just got this 1.5TB Hitachi 7K3000 drive from Newegg - Link

The 3TB version of this drive uses 5 600GB platters. This drive is a 1.5TB, so is it not using the same 600GB platters? Is it not really 1.5TB and actually 1.2 or 1.8?

Anybody have any info on this drive?

BTW... seems to be a very good deal on this drive. I was able to use the new account discount and got this drive for $44.99 shipped.

 

[FishAk]

The 7K3000 (HDS723015BLA642) 1.5TB drive uses three 667GB platters, and 5 heads.

http://rml527.blogspot.com/2010/10/hdd-platter-database-hitachi-35.html

 

[OCNewbie]

The 7K3000 (HDS723015BLA642) 1.5TB drive uses three 667GB platters, and 5 heads.

http://rml527.blogspot.com/2010/10/hdd-platter-database-hitachi-35.html

3 * 667 = 2001. I think that's accurate for the 2TB model, but not for this one.

I'm assuming this is 3 x 500GB platters, but can't be certain.

 

[FishAk]

The 1.5 and 2TB drives both have the same capacity.

The difference is that the 1.5TB drive reads only 5 disk surfaces, while the 2TB drive reads both sides of each disk.

 

[OCNewbie]

You lost me there. I guess I don't have a sufficient understanding of what exactly determines a drive's capacity and how that relates to platter size, etc.

 

[FishAk]

There is a disk or set of disks inside the drive. There is one or more heads that read or write to the disk surface. Like a record player, but you can have a needle on each side of each disk.

In your case, you have 3 disks. Each disk has the capacity for 667GB, or 333GB on each side of each disk. That is a total capacity of 2001GB, like you pointed out.

However, your drive only has 5 heads. Therefor it can only read and write to 5 sides out of the 6 sides that are available on the 3 disks. 5*333 = 1665, or about 1.5GB. The 2TB drive still has the same 3 disks, but it has 6 heads. This allows it to read and write to all 6 sides of the 3 disks. The link I gave you had the disk and head count of all modern HDDs I am aware of.

 

[OCNewbie]

I posted on that link you gave me, and the guy there helped clarify things more. I guess I had forgotten that each platter had it's own dedicated head, and I don't think I was aware that the platters could be written to on both sides. He mentioned something about short stroking, so that's something I'm still unfamiliar with. Thanks for clearing things up for me

 

[BTRY B 529th FA BN]

I wonder how it compared to the Samsung 1Tb F3 drive