[Bf-committers] Re: Re: Linux + Blender faq

GSR - FR bf-committers@blender.org
Sun, 1 Aug 2004 21:20:41 +0200


jjulio.pena@verizon.net.do (2004-08-01 at 1358.13 -0400):
> I felt like it should be mentioned:  With the Mesa drivers that came on
> RH9, I got a steady 2.1 fps on the game engine, after installing the

Ohh, on your RH9, with your NVidia card... and we all know there are
no more distros than RH and no more cards than NVidia... wait, there
are... :P Your 'in most distros the OpenGL drivers used are the "MESA
GLX IndirectĘ driver, which is OK for general work, but isn't
precisely the best choice for 3D work.' line is still not correct, it
is like saying that some nut&bolt pair is ok for normal uses,
supposing you are not going to ever use it.

On most distros the drivers used are DRI with Mesa falling back to
software only Mesa if card is not supported. If you get software only
Mesa, you have to figure why you got that, and solve the problem is
possible. But if you insist in converting a "my card is not supported"
into a "in general most distros out of the box suck at 3D", fine.

> official Nvidia drivers I get a steady 65 fps on the blender game
> engine  (tested on the e-cop game demo with a Gforce4 Ti 4200).

Let say it one more time: there are three, 3, possible cases:

- Mesa indirect, uses software Mesa to do everything, should work
  always, but is going to be slow and based in the speed of your CPU,
  mem bus, etc.

- DRI with Mesa, accelerated, uses the hardware to do operations.
  Distributions try to get it going if it detects a card supported. It
  says Mesa cos instead of coding all over again, they reuse Mesa,
  specially for shareable parts or things that the chip does not
  support at all. Speed is pretty acceptable, specially since you
  think that it is done by volunteers with no info or reduced info
  about the hardware.

- Proprietary from vendor or a company, uses hardware to do operations
  as well as software (things that the chip can not do have to be done
  in some way), should work fast, but is also famous for issues about
  badly installs, uncompatibility with kernels, vendor regressions or
  tricks that backfire. I think no distro provides this out of the
  box.

For some cards you are fucked and only have one, the first, software
based, for others you have two or even three options. NVidia cards are
only software or propietary, two options. But if you have an ATI 8500,
for example, you can choose from all the three methods. People should
always go for the hardware accelerated methods, but when they can
choose, they have to decide themselves if proprietary is what they
want, cos there is no warranty of getting a better result and maybe
they are fine with what they got.

That is the point I was trying to get accross: if a user gets hardware
acceleration and does not feel adventurous, there is no reason to
force a change. And in other cases, it is simpler to get DRI going
than the proprietary driver (maybe it is not working cos agp module
was not loaded, bad perms, bad option in config or some other simple
problem). While your "Blender is running way to slow on Linux, why?"
seems to only say "dude, you need proprietary cos it is the only that
goes fast".

Also, your method to discover what the user is running is over
complicated when compared to just typing "glxinfo" in a terminal
inside X11.

> Maybe the paragraph could be re-written so that I sounds less biased,
> but the fact that (on some times) you could get much better performance
> by substituting the Mesa drivers remain true and it would be negligence
> not letting the user to know it.

What you sound is like a reduced view of Linux driver status, after
all you seem to only know about NVidia cards and after trying. If you
had understood what was going on, you would have know that RH9 was
going to give you poor 3D, without having to check or install
anything. It should not sound biased, it should give the facts, all of
them.

You should provide links to ATI, NVidia Linux driver pages and the
HowTos that exist in the web, for being common cards now, as well as
to http://dri.sf.net/ & http://www.mesa3d.org/ (and read yourself
these two last sites, maybe you will realize what is going on).

>From me, last time I waste time trying to help with this issue.

GSR