Hi, I am not sure if this is the same problem, but I have an
application that uses large paged databases and have seen a slow down
on a higher end machine with a GeForce 7900  The slow down was only on
Windows, Linux ran fine.  After tracking it down, I found out that the
bottleneck was actually in the graphics drivers.  After installing an
older version of the drivers, the performance went back up again.
I've also seen the same behavior on a machine with a GeForce 8800 GTX.
 Unfortunately, I cannot find an older version of the drivers for that
card.  Again, I don't know if this is the same problem, but the
performance loss on a higher end machine rang a bell in my head.

Will

On Nov 10, 2007 12:31 AM, Akhtar Shamim <[EMAIL PROTECTED]> wrote:
> Dear All,
>
> Lately I had been seeing a very obscure problem with our OSG application.
>
> The application uses a very large Terra Vista paged terrain. I see the
> following two phenomena:
>
> 1. With all our old computers (i.e. computers having a single core CPU, 1 GB
> or less RAM and with graphics card < NVidia 6600) the application gives a
> constant update rate of 60 Hz. No problem with any refresh rate issues.
>
> 2. However, when I try the same application on a high end machine (Dual Core
> CPU or Quad Core CPU and with graphics card 7800 GT++) the performance is
> very poor and quite unpredictable. I looked at the CPU usages and found that
> the CPU usage is below 20 % for most of the CPUs. The application crawls at
> less than 6-7 Hz. However, if I change the BIOS setting to use only one CPU
> the application is back to normal and runs at constant 60 Hz.
>
> It seems to me that the database pager isnt working perfectly with multiple
> CPUs and gets deadlocked. I am very confused with this situation. For our
> deployment we have all new machines with dual and quad core CPUs and latest
> graphics cards.
>
> I would be very happy to hear suggestion/advice on how to solve this
> performance issue. To be honest I am quite stuck with the problem. I have
> tried compiling our application with OSG 1.2 and OSG 2.0. The phenomenon is
> the same.
>
>  Best regards.
>
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> osg-users@lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>
>
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