Matla quite slow while display 1024x1024 matrix

Good morning,

I face an issue while displaying simple matrix using such a script:

N=4096; a=ones(N,N);
figure(); mesh(a)

Matlab take minutes to display the surface and once dislayed it takes some more minutes to get out a frozen state.

I am not an expert at all but it seems to me it can be connected to the Graphical processor.

mine is NVIDI Quadro P1000, I don"t know whether this is a well sized one.

Many thanks for your feedback

Frederic

[Rik]

When I try this, I mainly see my CPU doing something.

You should note that the array you create is 4096x4096, not 1024x1024.

[Frederic Cleva]

Many thanks for the fast feedback Rick,

4096x4096, yes indeed, did I suggest that it was a 1024x1024 one?

I check the information given through the task managr and it says that the processor is occupied at 15% and memory requires 5 Go while the GPU is not that active. You are right.

I thought it could be related to graphical issue because any trial to move the 3D surface within the plot takes more than few minutes...

Did you get the same feature? Or does the 3D image gently follow when you drag with your mouse?

Thanks again for the help

Frederic

[Walter Roberson]

"Matla quite slow while display 1024x1024 matrix" was your title

[Frederic Cleva]

(oh I see... btw it is slow also with 1024x1024)

[Walter Roberson]

For me the 4K mesh takes a small number of seconds to bring up (roughly 8 seconds.) . Spinning it is a bit laggy but not so bad.

[Frederic Cleva]

Many thanks Walter,

is your computer something specifically boosted?

my laptop is a DELL recision 5530 with Intel Core i7-8850H CPU@ 2.6GHz / 16 Go RAM and two Graphics cards "NVIDIA Quadro P1000 " and Interl UHD Graphics 630. At least this is what mentionned from the peripheric manager.

I guess those values are not that bad

Frederic

[Walter Roberson]

No, my computer is a 2012 iMac

[Frederic Cleva]

Hum...

I run it on the laptop of a colleague with the same disapointing results. (for 4096^2 matrix)

[Frederic Cleva]

Hi everyone,

Some tracks:

when I run my script (4096x4096 matrix display) with matlab 2012 it takes only 10sec when I run whith older relaease (2018) it takes ages (minutes...).

Walter, do you run matlab 2012? or some not recent version?

In this specific case it seems worth to make the calculation with maltalb and ask another application fr the display

Many thanks

Frederic

[Bjorn Gustavsson]

In my experience matlab becomes very slow when tasked to plot large number of lines. That might also affect mesh. Could you aviod this irritation by using imagesc, surf or some other plotting-function?

[Frederic Cleva]

Many thanks Bjorn,

you make the point!!

Indeed with imagesc() it runs within few seconds instead of minutes for mesh() and surf() .

Frederic

[Walter Roberson]

I was running in MATLAB R2020b.

[Frederic Cleva]

what I know now:

matlab2020b + mesh(4096) + Imac2012 = few sec

matlab2012 + mesh(4096) + laptop DELL Precision5530 = few sec

matlab2018b + mesh(4096) + laptop DELL Precision5530 = few minutes

matlab2019a + imagesc(4096) + laptop HP ProBook (very basic) = few sec

I just installed matlab2020b, and now:

matlab2020a + imagesc(4096) + laptop DELL Precision5530 = few sec

and back to matlab2018b:why

matlab2018b + imagesc(4096) + laptop DELL Precision5530 = few sec

Conclusion:

my pb is solved but I don't understand how.

(By the way it is not specific to my laptop since a colleague faces the same issue)