[vtkusers] VTK performance with GeForce2 (RedHat 7.1 with NVidia drivers)

[Dave Reed]

> Date: Mon, 30 Apr 2001 17:49:46 +0200
> From: "Charl P. Botha" <c.p.botha at its.tudelft.nl>
> 
> On Mon, Apr 30, 2001 at 11:18:36AM -0400, Dave Reed wrote:
> > ------ AGP Info -------
> > AGP status:   Disabled
> > AGP Driver:
> > Bridge:       Generic Via
> 
> The NVidia drivers play it safe when it comes to AGP.  When the NV built-in
> AGP support detects a motherboard chipset which it doesn't trust all that
> much, it disables AGP.  Alternatively, you could try compiling kernel
> AGPGART (assuming that it supports your chipset) and try to have the drivers
> use this.  This is all documented in the nvidia packages (also how to get
> the drivers to use the built-in agp or kernel agpgart).


Yes, the documentation does mention compiling AGPGART support in the
kernel but didn't provide any details.  I'll have to look into this
more.



> > Can anyone confirm that I should get a more significant improvement
> > with the GeForce2 card?  And also, if anyone has any suggestions for
> 
> I would recommend testing your setup with some benchmark software, like
> "viewperf", and compare your results with the numerous published ones. FWIW,
> I get very good VTK rendering performance with a GeForce2 GTS at work and a
> GeForce2 MX at home, but that's all terribly subjective.


Yes, of course that's subjective. That's why I mentioned it was only
twice as fast as a TNT 2 card and much slower than my Sun Elite 3D at
work.  

I was borrowing the GeForce2 card and only had the card for a few
hours otherwise I would have tried some other benchmarks such as
viewperf.


> > problem and solved it. I'm wondering if the NVidia's kernel driver
> > isn't set up for the changes in the Linux 2.4 kernel. I found some
> > old messages that it wasn't setup for the 2.3.x development kernel but
> > they would have a fix so I would think it would be ready by now.
> 
> You should really make a habit of reading documentation.  NVidia 0.9.769
> supports being built and used on a 2.4.x system, although there are some
> issues with this combination in SMP setups.


Actually, I did read the README file that came with the NVidia drivers
That's how I got the drivers set up, found the lines for enabling AGP
support and checking /proc/nv/card0, etc..  I also read some other
information - somewhere (although I can't find it now), I ran across a
statement that mentioned a problem with 2.3.x kernels and using AGP
with the NVidia drivers and that a fix would be made shortly, but I
never found a statment saying that it was fixed. The NVidia web site
explicitly lists RedHat 7.0, but does not yet list RedHat 7.1 so I
thought maybe the 2.4.x kernel issue was still there.  I know it works
on a 2.4.x system because it works on mine, but I didn't know if the
AGP support doesn't work on 2.4.x systems and if that's my problem.

I'm just hoping that someone can confirm that a GeForce2 card will provide
better than a speed up of 2 vs. a TNT2 card and if the AGP support
would make a huge difference

Someone mentioned: http://www.barre.nom.fr/vtk/bench.html

in a private e-mail, but the results were on systems that varied so
much (and didn't provide other details like XFree 4.x vs. XFree 3.3.x)
that I couldn't get a good handle of what performance difference to
expect between the TNT2 and GeForce2 cards on a Linux system with the
NVidia drivers.

I'll drop it after this message since this is a little off-topic, but
if someone can confirm that I should get better than a speedup of two
or that I really need to get AGP support to get a decent speedup, I'd
love to hear that in a private e-mail.  I'm trying to decide if it's
worth buying a new video card (assuming it's all correctly
configured).  A speedup of two isn't worth $300 to me right now, but I
expect that something isn't set up correctly (even though the kernel
driver is loaded and ldd reports it's using the correct libraries).
The only thing I can figure is the AGP support makes the difference.

Thanks,
Dave