degradation of transfer speed when copying large files

[Frank Schwarz]

Hi

When copying/moving large files between hard disks, I notice a considerable degradation of transfer speed after the first 600 mb - a sudden drop of 50 mb/s to about 10 mb/s.

Salamander version is 2.52 beta 1.

A bug?

Cheers,
Frank

[Jan Rysavy]

Hi Frank, It could be simply fragmentation issue. The source file or the destination space could be heavily fragmented.

Try to copy your file using Windows Explorer and let us know. Please, measure the total copy time in AS and WE.

Note: also the antivirus could cause this problem.

[Frank Schwarz]

To copy a 1.6GB file, Salamader take 1:30 min, Explorer 1:40 min. Fragmentation should not be a problem. Looking a the transfer speed in Salamander, there is a significant drop after the first 500MB.

Kind regards,
Frank

[Jan Rysavy]

So it looks like standard transfer speed for your PC (according to the Explorer speed). I don't see the problem here...

[Frank Schwarz]

OK. Perhaps this is a feature request. I do not know anything about the internals how Salamander copies files. I leave this to your judgment.

Interestingly, TotalCommander, on my PC, requires 50 seconds for the same action.

Cheers,
Frank

[Klettermaxe]

Could it be that the file was still partially cached when you copied it with Total Commander?

I copied a 574 MB file from a heavily fragmented partition to another partition on the same harddrive in 80 s (yes, only 7 MB/s). After deleting it on the destination partition and copying it immediately again, it took only 10 s. The time was still 10 s after viewing a 348 MB Tiff-file.

After a restart, xcopy took also approx. 80 s and 10 s for the second copy. I cannot believe that TC has so damned smart copying routines.

AS 2.52 beta 1

Best wishes
Klettermaxe