Re: [Enigma-devel] Re: Mac performance problems on some levels

[Ronald Lamprecht]

Hi,

Sidney Markowitz wrote:
> Ronald Lamprecht wrote, On 2/6/07 8:17 AM:
>
> > Sidney could you please start the trunk version on both Macs with the 
> > option "--showfps". Please try to play "Bright Dots", "Deserted Island" 
> > and "Wolf Among Sheep" (Development Group, Experimental Levelpack) on 
> > both Macs with approximatly the same marble speed and report the average 
> > fps values shown on the screen. I would like to know if there is still a 
> > critical difference in both Macs.
>
> I played all three levels on both the Intel Mac and the PPC. All of them
> except one ran around 50fps with some quick slowdowns as low as into the
> 30's that were almost over before I could read the numbers. So mostly
> around 50.
>
> The one exception was Wolf Among Sheep on the PPC. That was unplayable,
> starting at 2 or 1 fps and then going to 0. The command line terminal I
> started it from showed error messages "Whoa, system is overloaded!" (I'm
> paraphrasing from memory, might not be those exact words).
>
> I find it interesting that the fps on the others was the same on both
> machines even though the Intel Mac is much faster and has more memory
> than the PPC Mac.

O.k. - that is all like I expected it to be. Some explanations:

Enigma just uses as many resources as necessary. If the level is easy to 
calculate and the CPU is fast enough Enigma steps aside and leaves the 
remaining time for other processes. I do run Enigma in window mode with 
compilations or bittorrent running in the background.

If the level requires too many calculations due to number of actors, 
slow SDL or an old CPU the physical engine keeps running as fast as 
possible but the display engine steps aside with lower framerates.

If the situation gets worse the physical engine is no longer able to run 
a correct physical simulation and writes messages of "overload". In 
these situations the display engine won't display more than a single 
frame per second.


"Wolf Among Sheep" is used as a pure performance testlevel. It was not 
playable with 0.9* and 1.0* on any reasonable system. But it is nearly 
perfect on modern CPUs with 1.1 on OS like Windows.

I found several reports about SDL performance problems on Mac OSX. All 
blitting seems to be done within SDL without using the GPU. SDL tried to 
improve the situation, but may that not all Macs have been affected.

One experiment that remains to be done is to check the Fullscreen/Window 
mode dependency of the performance problem.

For the development of Enigma we can only minimize the blitting or 
switch to OpenGL that should not show up these problems at all.

- Ronald