How to calculate the capacity of a disk drive

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SUMMARY

The discussion focuses on calculating the capacity of a disk drive with 6 platters, each recording data on both sides, resulting in 12 read/write heads. The total capacity is calculated as 512 bytes per sector, with 9 sectors per track and 3000 tracks, leading to a total of 165,888,000 bytes. The conversation clarifies the distinction between gigabyte (GB) as 1,000,000,000 bytes and gibibyte (GiB) as 1,073,741,824 bytes, emphasizing the importance of using the correct definition based on the context.

PREREQUISITES
  • Understanding of hard drive architecture, including platters and read/write heads
  • Knowledge of data storage units, specifically bytes, kilobytes, megabytes, gigabytes, and gibibytes
  • Familiarity with basic arithmetic operations for capacity calculations
  • Awareness of historical context regarding data measurement standards
NEXT STEPS
  • Research the differences between gigabyte (GB) and gibibyte (GiB) in data storage
  • Explore hard drive architecture and how it affects performance and capacity
  • Learn about data storage calculations and conversions between different units
  • Investigate the evolution of data measurement standards and their implications for consumers
USEFUL FOR

This discussion is beneficial for computer science students, hardware engineers, data storage professionals, and anyone involved in understanding or calculating disk drive capacities.

TanyaQ
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Good morning, I got a question like this-

"A hard drive has 6 platters, each platter records data on both sides. There are 3000 tracks of nine sectors each. Each sector stores 512 bytes of data. How many read/ write heads are there and what are the capacity of the drive(in Gigabytes)?"

I understand so far the read/ write heads= 2*6 =12
The capacity of the drive= 512*9*3000*12=165888000bytes

I understand to where they got this answers but its not finish as I need to get it to the gigabyte and this find the capacity of the disk. Can you please assist I don't understand ?
 
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TanyaQ said:
I need to get it to the gigabyte
You've GOT it to the gigabyte, given the information you were given.

Why would you need more than 6 significant digits anyway?

Why do you believe that the numbers given are not exact?
 
A gigabyte is 1,000,000,000 bytes. Does this help?
 
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There are two definitions for GigaByte, one is as @phyzguy says at post #3 and the other is equal to

##2^{30}=1,073,741,824## bytes.
 
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Delta2 said:
There are two definitions for GigaByte, one is as @phyzguy says at post #3 and the other is equal to

##2^{30}=1,073,741,824## bytes.
In recent years (starting at around 1998), in order to avoid confusion, new terms were created such as "gibibyte," as opposed to "gigabyte," where

1 gibibyte = 1 GiB = 2^{30} bytes = 1,073,741,824 bytes

in contrast to

1 gigabyte = 1 GB = 10^9 bytes = 1,000,000,000 bytes.

However, -- and this is important --, the "correct" answer may depend on how old your textbook is. This whole kibi, mebi, gibi, tebi, pebi, exbi, zebi, and yobi naming convention wasn't universally adopted by everybody.

For the longest time, "gigabyte" might have meant 1,073,741,824 bytes, or it might have meant 1,000,000,000 bytes, and which one was chosen by the hard-drive manufacturer was whichever one made the product look better.

So my advice to you, @TanyaQ, is whichever convention you use, be sure to back it up with your definition. (Or better yet, just answer in terms of both conventions [GB and GiB] to avoid confusion. :smile: )
 
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Oh, and @TanyaQ,

Welcome to PF! :welcome:
 
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collinsmark said:
In recent years (starting at around 1998), in order to avoid confusion, new terms were created such as "gibibyte," as opposed to "gigabyte," where

1 gibibyte = 1 GiB = 2^{30} bytes = 1,073,741,824 bytes

in contrast to

1 gigabyte = 1 GB = 10^9 bytes = 1,000,000,000 bytes.

However, -- and this is important --, the "correct" answer may depend on how old your textbook is. This whole kibi, mebi, gibi, tebi, pebi, exbi, zebi, and yobi naming convention wasn't universally adopted by everybody.

For the longest time, "gigabyte" might have meant 1,073,741,824 bytes, or it might have meant 1,000,000,000 bytes, and which one was chosen by the hard-drive manufacturer was whichever one made the product look better.

So my advice to you, @TanyaQ, is whichever convention you use, be sure to back it up with your definition. (Or better yet, just answer in terms of both conventions [GB and GiB] to avoid confusion. :smile: )
Thank you
 
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TanyaQ said:
Thank you
I never know all these. Now I do. Thank you very much
 
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phyzguy said:
A gigabyte is 1,000,000,000 bytes. Does this help?
Sooooo much. Thank you
 
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  • #10
phyzguy said:
A gigabyte is 1,000,000,000 bytes. Does this help?
 
  • #11
Yes
 

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