[AD] Framerate under the 4.1.x WIP Windows builds is mysteriously slow.

[Andrei Ellman <ae-a-alleg@xxxxxxxxxx>]

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.

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