*-* On Fri, 14 Aug 2009, at 00:12:36 -0500,

*-* In Article <Xns9C66E1EE2B9FDLarrynospammenet@216.196.97.130 >,

*-* Larry wrote

*-* About Re: Harddrive install question : size?

> Ben Myers <(E-Mail Removed)> wrote in

> news:h62r1n$bq3$(E-Mail Removed)-september.org:

>> Larry wrote:

>>> Insatalled a 160gb wd in a gateway MX6440 laptop and all i see is

>>> 149gb totel size with 145gb free. how do i get the full drive?

>>> Thanks Larry

>> It all depends on how you do the math. But no matter what, 1K does

>> not equal 1000. But then there's Microsoft math, a leftover from

>> the days when assembly programmers would save some clock cycles by

>> avoiding a time-consuming divide by 1000. Instead, they shifted

>> the number right 10 bits (or dropping the rightmost 10 bits, if

>> you'd rather)... Ben Myers

> Thanks Ben ! So 149 is the full size!. It would help if they just

> used real numbers. You see 160 but it's a illusion.
I wouldn't call it an illusion. It's the difference between

decimal (powers of 10 - 10, 100, 1,000, 10,000, etc.) and binary

(powers of 2 - 2, 4, 8, 16, 32, 64, etc.) math. In decimal math,

kilo- is 1,000. In binary math the closest power of 2 is 1,024, so

that came to be known as kilo- as the closest approximation.

Unfortunately, as you go up the scale, the difference becomes much

greater.

Decimal Binary

KiloByte (KB) 1,000 Bytes 1,024 Bytes

MegaByte (MB) 1,000,000 " 1,048,576 "

GigaByte (GB) 1,000,000,000 " 1,073,741,824 "

Hard drive manufacturers use decimal numbers to measure the

capacity of drives, so your 160 GB drive is 160,000,000,000 bytes.

Computers are binary devices (1/0, +/-, yes/no, however you want to

think of the process), so they "see" hard drives in binary terms, so

your computer sees that "160 GB" drive as

160,000,000,000/1,073,741,824 (or 149.0116) GB. The same relationship

applies to all hard drives (and other storage devices) whether OEM,

replacement, or whatever. As you can see from this example,

manufacturers measure capacity decimally because it allows them to

claim a larger capacity for a given size drive, and years ago, when

the practice started, the differences weren't as significant.

> Thanks Larry
You're welcome.

Ken Whiton

--

FIDO: 1:132/152

InterNet:

(E-Mail Removed) (remove the obvious to reply)