Difference between hard drive disks space

[aandril]

All 3.5" disks and all 2.5" disks literally look the same.

 

Why is there a difference in sizes? What makes them different?

 

I searched Google but no results on why sizes differ for an identical disk/s.

[-rascal-]

4 minutes ago, aandril said:

All 3.5" disks and all 2.5" disks literally look the same.

 

Why is there a difference in sizes? What makes them different?

 

I searched Google but no results on why sizes differ for an identical disk/s.

 

2.5" are 90%+ used in laptops.

3.5" are commonly used in desktop PCs.

 

There is nothing different, just smaller in physical size.

Laptops CANNOT fit 3.5" drives.

[aandril]

5 minutes ago, -rascal- said:

 

2.5" are 90%+ used in laptops.

3.5" are commonly used in desktop PCs.

 

There is nothing different, just smaller in physical size.

Laptops CANNOT fit 3.5" drives.

That's not the question.

[aandril]

The disks in drives are exactly the same.

 

Ie 500GB disk look exactly like 1TB disks.

 

Why do they differ in size if the look the same?

[-rascal-]

3 minutes ago, aandril said:

The disks in drives are exactly the same.

 

Ie 500GB disk look exactly like 1TB disks.

 

Why do they differ in size if the look the same?

 

Ohhh...storage capacity size.

HDDs have *platters* (or disks) inside them.

The disks can be higher density (each disk can store more data) and/or there is more of these disks.

 

As mechanical HDD technology improves, we can put more data per platter -- even though the physical size of said platter remains the same.

I think as of recently, we are able to store 2TB (?) of data on each platter ... compared to like 1TB or 500GB a few years ago.

 

[aandril]

Hmmm but what makes them higher density?

 

How do computers recognize their sizes?

 

What about manufacturing error? If it's 0.05MB differential, how would a computer know this?

[-rascal-]

13 minutes ago, aandril said:

Hmmm but what makes them higher density?

 

How do computers recognize their sizes?

 

What about manufacturing error? If it's 0.05MB differential, how would a computer know this?

 

I am not too sure how the PC recognizes the drive capacity, but would assume there is a set of register values or a set of information hard-coded onto the drive.

When the computer start-up the drive, it would read these values to determine the drive size.

 

For your section question, you might need to reach out to someone who knows more about the inner workings of a mechanical HDD...

...or even get in touch with the Seagate / Western Digital folks on the forums here.

 

Similar to a SSD, a mechanical HDD has a millons/billions of data cells.

Each cell is 1-bit of data -- if the cell is magnetized, it will a 1 bit, if demagnetized, it is a 0 bit.

[aandril]

8 minutes ago, -rascal- said:

 

I am not too sure how the PC recognizes the drive capacity, but would assume there is a set of register values or a set of information hard-coded onto the drive.

When the computer start-up the drive, it would read these values to determine the drive size.

 

For your section question, you might need to reach out to someone who knows more about the inner workings of a mechanical HDD...

...or even get in touch with the Seagate / Western Digital folks on the forums here.

 

Similar to a SSD, a mechanical HDD has a millons/billions of data cells.

Each cell is 1-bit of data -- if the cell is magnetized, it will a 1 bit, if demagnetized, it is a 0 bit.

I'm confused by your first answer.

If a computer needs to be told what size a disk Is, how did the manufacturing company know how much the disk is and set the value?

 

How did someone know what the size of the manufactured disk was? There's no tool I've heard of that has, or even can state that...

 

Though I suppose I missed the point of history and research.

 

After all the word bytes had to have come from somewhere.

 

I'm assuming computer scientists designed programs and labeled them a size when creating storage devices and tested how many of the programs could be put on it.

 

AMAZIN

[-rascal-]

21 minutes ago, aandril said:

I'm confused by your first answer.

If a computer needs to be told what size a disk Is, how did the manufacturing company know how much the disk is and set the value?

 

How did someone know what the size of the manufactured disk was? There's no tool I've heard of that has, or even can state that...

 

Though I suppose I missed the point of history and research.

 

After all the word bytes had to have come from somewhere.

 

I'm assuming computer scientists designed programs and labeled them a size when creating storage devices and tested how many of the programs could be put on it.

 

AMAZIN

 

Well you first need to understand what a register is -- either software or hardware.

Either that, or it is programmed into a separate bit of RAM / EEPROM / ROM.

Information may include drive capacity, manufacture date, manufacture location, manufacturer brand, etc.

 

If you disassemble a drive, you will see there is memory and a processor within it...and a little circuit board.

A HDD is not just a brain-less spinning magnetic brick.

[Pickles von Brine]

There are a few things that determine drive size:

 

Firmware of the drive itself. I use to work in data recovery and a common practice we used was editing the total LBA available to make 500GB drives out of 1TB drives. Useful if you just need to image the exact number of LBAs. Plus, it prevents any software from reading beyond disk bounds. 

 

The other is aerial density of the platters and number of platters used. A prime example is a platter that has a 500GB capacity. You may see the same platter used in a 500GB drive, 2 in a 1TB and 4 in a 2TB. 

 

There are a few others but mainly these are the big two.