What do different patterns mean in Windows 8 file copy dialog

When copying or extracting files, Windows 8 shows the chart with the speed of the operation.

I noticed several patterns:

• Randomness,

• High speed at the beginning, then low speed during the most part of the operation,

• Mostly constant speed.

1. Randomness/nice mountains.

2. High speed at the beginning, then low speed during the most part of the operation.

3. Low speed at the beginning, then high speed during the most part of the operation.

(Similar to the previous image, but inverted)

4. Mostly constant speed.

(Same as previous image, but without the fast start)

I'm curious, what each of those patterns mean?

Do some indicate that there may be a problem with hard disk performance?

Why the nearly constant speed is so rare, even when copying a single large file from and to a spinning drive, or when copying a single large file or a bunch of small files from and to an SSD?

Solution 1:

Several things could be going on:

1. Hard drive caching could be giving a nice initial bump
2. Other things could be getting written to the drive at the same time (causing randomness)
3. For whatever reason, caching did not occur, and nothing else is getting written to the drive.
4. Something else to keep in mind is that it is faster (in extreme cases much faster) to do things to a small amount of large files, as opposed to a large amount of small files.

Something else to look at is the task manager, and see if that shows these same patterns. If it shows the randomness one when you are copying a file then something else is going on.

None of this indicates a problem, but rather more is going on than you see in that dialog.