Hi,
When testing my app on a 32 bit desktop (Win2K) I find that the frame rate
is about 70 fps, but the cpu usage is about 75%. I assume this is either
because the blit to the display is asyncronous, or its waiting for the
vertical retrace.
But when debugging I set the environment variable to windib the frame rate
goes up to 102 fps with full cpu usage.
Im puzzled as to why Im seeing these numbers. Since the app is capable of
rendering 100+ frames per second, I would expect it to max out at the
refresh rate of my monitor (85) when using the directx video driver.
Could someone shed some light on this for me…
Thanks,
Will McGugan
Will McGugan wrote:
Hi,
When testing my app on a 32 bit desktop (Win2K) I find that the frame rate
is about 70 fps, but the cpu usage is about 75%. I assume this is either
because the blit to the display is asyncronous, or its waiting for the
vertical retrace.
Are you sure that your screen is really at 85hz ? 70 fps sounds like
70Hz to me…
Stephane
When testing my app on a 32 bit desktop (Win2K) I find that the
frame rate
is about 70 fps, but the cpu usage is about 75%. I assume this is either
because the blit to the display is asyncronous, or its waiting for the
vertical retrace.
Are you sure that your screen is really at 85hz ? 70 fps sounds like
70Hz to me…
Its definately 85, going by display settings.
If I disable most of the graphics code the frame rate goes above 85. Which
would suggest it isnt doing any vsyncing.
A friend of mine said he has seen the same behaviour with DDraw, it appears
to spend a good deal of time waiting for something. The only thing I can
think of is that the primary surface is being locked by another process, but
I see this even with all non-essential processes shut down.
This is puzzling. Does anyone else see the same behaviour??
Will McGugan