| Re: [AD] Framerate under the 4.1.x WIP Windows builds is mysteriously slow. |
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- To: alleg-developers@xxxxxxxxxx
- Subject: Re: [AD] Framerate under the 4.1.x WIP Windows builds is mysteriously slow.
- From: Oscar Giner <oginer@xxxxxxxxxx>
- Date: Fri, 4 Mar 2005 03:48:25 +0100
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I changed your logic loop with this one:
if(nLogicCount < retrace_count)
{
nLogicCount++;
bOKToDraw = TRUE;
}
and then it worked (it showed 85fps, with a 85Hz refresh rate). If I
change the if with a while then it doesn't. This seem to show that
retrace_count is not updated as often as it should, because it does
two loops (I also get around 35fps).
In other words, a bug or not, retrace_count is not very accurate (it's
increase 85 times per second (in my case) but not evenly).
The accuracy is pretty low, however.
On Tue, 01 Mar 2005 15:24:27 +0100, Andrei Ellman
<ae-a-alleg@xxxxxxxxxx> wrote:
> Hi,
>
> I have written a simple test-program that synchronises the program to
> retrace_count and prints out the screen's refresh-rate (or simulated
> refresh-rate), and howmany FPS it achieves. As there is no program logic
> that's updated and no rendering (apart from printing the refresh-rate
> and FPS), you would expect the FPS to be equal to the refresh-rate, but
> under 4.1.18 (and 4.1.11) on Windows, this is not the case.
>
> In 4.0.3 under Windows 2000 and 4.1.18 under DJGPP, the FPS is the
> retrace rate (60 on W2K and 70 on DJGPP). However, in 4.1.18 under
> Windows 2000 (Direct X 9.0c), it's 37 FPS, and on 4.1.18 under Windows
> 98 (Direct X 8.1), it's 34 FPS (the retrace-rate was 60Hz in both cases).
>
> I am using a Matrox Marvel G400 TV graphics card. My PC is a 600 MHz
> Athlon with 256 MB of ram. Attatched is the test-program I used.
>
> Incidentally, this problem might explain why the program in the
> following thread on Allegro.cc was getting no higher than 39FPS.
> http://www.allegro.cc/forums/view_thread.php?_id=462934
>
>
> AE.
>
>
>
--
Oscar Giner (oginer@xxxxxxxxxx)
http://www.oginer.tk