100% CPU usage

[Midnight]

Ok I understand Irrlicht updates like every second or something.

It's a rendering engine it makes sense.

But my menu only requires the GUI be updated every so often and even without a scene manager implimented it still uses 100% of the available cpu to update the GUI. (or at least I think thats whats happening)

So the question is, how can i reduce the cpu usage?

[Guest]

my irrlicht applications only use 50%-56% cpu usage. i guess you cannot turn it off.

[Midnight]

well how to you obtain that?

I have a 2.4 pentium with exact stats as yourself almost.


unless your gpu is pci and helps your cpu.. how do you do that? lol

[bitplane]

in winblows only, put a short Sleep() in your main loop.
I dunno what the equivelant in linux is though

[Midnight]

thanks I knew it was something like that.

couldn't seem to find anything on google.

[Midnight]

thanks that worked AWSOME.. the frames per second have gone down 1/3 but the cpu usage drop is Dramatic it's using 0% cpu when idle and thats with direct x 9 and the 3d background... other then the fps drop I see no reason not to do it this way.

[MBA]

hi

just for completenes, the equivalent to the windows Sleep() on a *nix system is the usleep().
The sleep() defined in unistd.h has only seconds precision while the usleep() takes a msec argument. The highest precision is about 10 msec dependent on the granularity of the linux scheduler. When performing a usleep your process is rescheduled and the Linux scheduler (for the x86 architecture) usually takes at least about 10-30 milliseconds before it returns control to your process.

best regards
mba

[Andreas]

I think the disadvantage of using a sleep is, that the game will run slow on less powerfull machines.

Or is there a way to determine the sleep argument (i.e. sleep for 1, 2, 3,... seconds) depending on the CPU speed??

[Midnight]

so let me get this straight usleep() works on both windows and linux?

so it's good to use this instead?

[luckymutt]

put a short Sleep() in your main loop.

is there a parameter that goes with this? expressed in time(ms) or something?

when its running at 400+ fps to begin with, I don't see how a 30% drop in the frame rate would be a big deal.

[bitplane]

thanks MBA... I'll push it one further with a half-arsed preprocessor macro then

Code: Select all

#ifdef LINUX
#include <unistd.h>
#define Sleep(x) usleep(x)
#else
#include <windows.h>
#endif

luckymutt- yes, it's "Sleep(time_in_ms)". Andreas, see this thread for frame limiting info http://irrlicht.sourceforge.net/phpBB2/ ... php?t=8246

[MBA]

so let me get this straight usleep() works on both windows and linux?
so it's good to use this instead?

The unistd.h defines standard routines used in a unix environment, and it contains unix specific code. You probably wouldn't use it on a windows machine.


"Do not #include <unistd.h> as it contains UNIX-specific definitions. At the very least, check with your Windows environment before using functions or constants from <unistd.h>."

From:
http://www.opengl.org/resources/tutoria ... de389.html


But you would use it when doing something portable like the portable-macro bitplane was suggesting

[Fred]

How many ms are you sleeping?

[Midnight]

#ifdef LINUX
#include <unistd.h>
#define Sleep(x) usleep(x)
#endif
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif


so then would this be proper?

I'm sleeping Sleep(50); for the menu which is only GUI (no 3d not even a scene manager)

and I'm sleeping Sleep(10); for the Guice application to reduce the lag to a minimum where the menu has a touch of lag but really it doesn't seem to hurt anything and reduce cpu to almost nothing.

I have another question will it lag more on a slower system then my own?

[Spintz]

sleep(0) is commonly used in threading models. What it does for a thread is drops the cswitch which allows other threads to start running.