Samsung np-q1ex User Manual page 7

About the Product Capacity Representation Standard
About HDD Capacity Representation
The capacity of the storage device (HDD, SSD) of the manufacturer is calculated
assuming that 1KB=1,000 Bytes.
However, the operating system (Windows) calculates the storage device capacity
assuming that 1KB=1,04 Bytes, and therefore the capacity representation of the
HDD in Windows is smaller than the actual capacity due to the difference in capacity
calculation.
(E.g. For a 80GB HDD, Windows represents the capacity as 74.5GB,
80x1,000x1,000x1,000 byte/(1,024x1,024x1,024)byte = 74.505GB)
In addition, the capacity representation in Windows may be even smaller because some
programs such as Recovery Solution may reside in a hidden area of the HDD.
About Memory Capacity Representation
The memory capacity reported in Windows is less than the actual capacity of memory.
This is because BIOS or a video adapter uses a portion of memory or claims it for
further use.
(E.g. For 1GB(=1,024MB) memory installed, Windows may report the capacity as
1,0MB or less)