Last week I bought a new 1TB WD external hard disk. I was not much surprised to see my hard disk showing up only 931.322 gb of available space, but as usual wondered what must be the theory behind it. Well it turned out to be pretty simple, here you go.
Disk manufacturer takes for granted
1KB = 1000B, 1MB = 1000KB, 1GB = 1000MB and so on!
Well, software inbuilt in your computer counts space in multiples of 2, ie 2 bytes, 4 bytes, 8 bytes and so on. So
1KB = 2 power 10 bytes ie 1024 Bytes
1MB = 2 power 20 bytes ie 1024 KBytes ie 1024x1024Bytes
Let's do a bit more math now!
My hard disk manufacturer provided me with 1TB of space
ie 1TB = 1000x1000x1000x1000 Bytes
But my software counts 1KB as 1024 Bytes so the available 10 power 12bytes must be devided by 1024 power 4 bytes to get available space as seen by my software!
(10 power 12 )/1024/1024/1024/1024 which amounts to .9313 TB ie 931.322GB!!
This is where the remaining 68.67GB has gone! This missing space increases with higher capacity hard drives and decreases with lower capacity hard drives.
Thank you for reading!
Credits : my dear friend Suprith!