Originally Posted by StringCheesian
What happens if you install the older GCC that debian is using, and use it to compile a 2.6.30 kernel to downgrade to?
That way they would both have roughly the same kernel compiled with the same version of GCC.
I also notice they are also using different filesystems, but that shouldn't matter.
EDIT: Does phoronix test suite compile stuff before testing? If so, the benchmark application itself would be effected by the version of GCC it used.
EDIT #2: And kernel config options like Preemption model or Timer frequency might make a difference too.
The package manager of sabayon provides only kernel 2.6.31. I could ask them but it will take long until they are convinced to add the 2.6.30 kernel. As for the compilers it should not make a difference. The code is purely OpenGL code. and I think it comes precompiled. Even if it didn't different versions of compilers could not make such a difference on OpenGL code. We are talking about differences by a factor of 2 or more. Everything that Sabayon compiles is compiled with -O2. No compiler flag combination can provide code twice as fast as the one with -O2 especially when it comes to OpenGL commands.
I think it is a kernel issue.
Do you have an Nvidia card yourself? You could try the phoronix test suite running the same benchmark and tell us what you get.
The first thing you ask me to do is too much to do as it requires a lot of work. I could however run a diff on the .config files of both kernels and see what is different.