runtime load mat-file not proportional to size?

It takes me 0.08 seconds to load a .mat-file with 138MB containing 367 nx1 double arrays.

But 0.57 seconds to load a .mat-file with 3MB containing one nx250 double array.

Why is that?

I changed the structure of the file to be faster. Now i am slower.

Thanks in advance!

Answer 1

[Christian Tieber]

Same story if i just load, save and reload:

disp('load matfile: ');
tic
data = load(fullmatpath);
toc

dataPath = ['data\',filename];
save(dataPath, 'data');

disp('load data: ');
tic
load(dataPath);
toc

load matfile:

Elapsed time is 0.086910 seconds.

load data:

Elapsed time is 0.580817 seconds.

[Christian Tieber]

hint: it has nothing to do with the path. Both paths point to the same drive.

[Jan]

If you do not use an absolute path name, Matlab searchs in its PATH.

Can you provide some test data, e.g. created by RAND, which reproduce your observations?

Answer 2

[Jan]

Do you saved in compressed or uncompressed format? In v6, v7 or v7.3 style?

Is the file contained in the disk cache of your HDD or SSD? This will influence the speed massively also.

[Christian Tieber]

"Do you saved in compressed or uncompressed format? In v6, v7 or v7.3 style?"

Tried all of them with similar results.

"Is the file contained in the disk cache of your HDD or SSD? This will influence the speed massively also."

I dont know. How can i find out?