Radeon Gallium3D MSAA Performance (R300g)

[marek]

No, I tested with the defaults of --enable-debug, i.e. -O0.

[oibaf]

No, I tested with the defaults of --enable-debug, i.e. -O0.

Ah, OK, so your big performance drop is due to compiling with -O0. So --enable-debug + forcing -O2 shouldn’t be much slower than without debug?

[marek]

Ah, OK, so your big performance drop is due to compiling with -O0. So --enable-debug + forcing -O2 shouldn’t be much slower than without debug?

For your PPA, I prefer not to use --enable-debug and -DDEBUG at all. -DDEBUG is for development only, there's a lot of sanity checking, which reduces performance; not as much as --enable-debug, but it's noticable. --enable-debug only gives you good gdb experience, other than that it's useless.

You said: "torcs 7.3 with debug 6.7 fps", that's with -O2 and -DDEBUG if I understood correctly. If you convert it to percents, you get 8% worse performance with -DDEBUG - that is the cost of all the sanity checking. That's is too much. Imagine every user using your PPA gets 8% lower performance...

[agd5f]

I suspect the slowness of Phoronix test here is due to this.

That doesn't explain the slower results with MSAA disabled.

[oibaf]

The torcs test was very informal, I just took the on screen fps value after starting a game, the real gap may be smaller (or bigger). Anyway I'll see to disable it.