WineD3D performance

[Stefan Dösinger]

Am 14.03.2013 um 20:07 schrieb Graham Knap <graham.knap at gmail.com>:
> I would like to try to help with improving the performance of
> StarCraft II on Wine. I'm working with a friend. Over the past couple
> of weeks, we have tried to read whatever documentation we could find.
> We have tried a couple of different approaches to profiling, without
> much success.
That's great :-)

Note however that improving performance is not a weekend's job. It needs a lot of careful profiling, testing and bugfixing.

> Can anyone offer some hints on how to find the most significant causes
> of the performance difference? Any tips for effective profiling or
> tracing?
Depending on your settings, you may be CPU or GPU limited. A rule of thumb way to find out is to change the game's resolution - if increasing the resolution causes a big framerate drop, you're probably GPU limited. If the framerate stays the same, you're CPU limited.

In the GPU limited case, improving the situation requires a tedious work to find shaders that execute slower, finding out why they are slower and then fixing things. It also needs double-checking with other games and GPUs to make sure that you're not optimizing one game at the cost of another.

In the CPU limited case, I believe the main reason is that native is able to move a lot of the CPU-side work to a different thread, thus utilizing two CPU cores. You can test that theory by forcing Windows to run with one CPU only (use msconfig for that) and comparing performance again.

Aside of the worker thread, there may be some parts of the wined3d code that can be optimized. Like the GPU side work, this requires a lot of careful testing, fixing and double-checking.

Stefan