Overview
You may notice in the CrashPlan app that the amount of space used at a particular destination differs from the amount used as shown in the CrashPlan console for the exact same destination. The reason is because the CrashPlan app displays storage values using a different calculation method than the CrashPlan console. This article explains the difference.
Calculation background
The CrashPlan app calculates storage amounts using a base-10 counting system. In this system, a kilobyte is 1000 bytes, a megabyte is 1000 kilobytes, and a gigabyte is 1000 megabytes.
The CrashPlan console calculates storage amounts using a base-2 counting system, or binary. In this system, a kibibyte is 1024 bytes, a mebibyte is 1024 kibibytes, and a gibibyte is 1024 mebibytes. These totals are calculated by the exponential power of two. For example, 210 = 1024.
Storage displayed in the CrashPlan app versus the CrashPlan console
The CrashPlan app and the CrashPlan console both display storage size as "MB" or "GB", but those acronyms mean different things depending on where they are displayed:
- In the CrashPlan app, storage is displayed in megabytes or gigabytes (base-10 system).
- In the CrashPlan console, storage is displayed in mebibytes or gibibytes (base-2 system).
So, for example, while your CrashPlan app shows that the space used at a particular destination is 1.5 GB (1.5 gigabytes), your CrashPlan console will show the used storage at the exact same destination as 1.3 GB (1.3 gibibytes). It's the same amount. It's just measured in different ways.