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View Full Version : 8x Antialiasing Turns Off Multi-GPU Mode on nVidia GEForce 7950


Will
December 24th 07, 12:09 AM
Starting about a year ago, nVidia modified its GEForce 7 drivers to remove
the 8xS antaliasing mode, which was compatible with multi-GPU performance.
Now you are forced to choose in the nVidia control panel between 4x and 8x.
4x gives mediocre antialiasing. 8x gives a good visual result, but if you
select 8x antialiasing you get a modal dialog warning you that this mode is
incompatible with multi-GPU support. Why would nVidia put such an awful
restriction into the drivers for this card? In effect, to get good visual
qualities you have to cripple the card's potential performance? To make a
confusing issue utterly unintelligible, if you then switch from 8x to 4x
antialiasing, you get a different modal dialog that warns you that going
from 8x to 4x will compromise the best "multi-GPU performance". This
directly contradicts the earlier dialog when going from 4x to 8x, by
implying that at 8x you can get a multi-GPU mode working.

At minimum, nVidia needs to clean up the text and explanations in these
dialogs. It's a mess. Can someone explain what these warnings actually
mean?

Can someone explain what are the implications of turning off multi-GPU
performance modes? If I want 8x antialiasing for visual quality, is there
any way to get both GPUs on the 7950 working towards rendering a scene?
Maybe in this case I would be forced to select one of the alternate frame
rendering modes 1 or 2?

--
Will

Mr.E Solved!
December 24th 07, 12:49 AM
Will wrote:
> Starting about a year ago, nVidia modified its GEForce 7 drivers to remove
> the 8xS antaliasing mode, which was compatible with multi-GPU performance.
> Now you are forced to choose in the nVidia control panel between 4x and 8x.
> 4x gives mediocre antialiasing. 8x gives a good visual result, but if you
> select 8x antialiasing you get a modal dialog warning you that this mode is
> incompatible with multi-GPU support. Why would nVidia put such an awful
> restriction into the drivers for this card? In effect, to get good visual
> qualities you have to cripple the card's potential performance? To make a
> confusing issue utterly unintelligible, if you then switch from 8x to 4x
> antialiasing, you get a different modal dialog that warns you that going
> from 8x to 4x will compromise the best "multi-GPU performance". This
> directly contradicts the earlier dialog when going from 4x to 8x, by
> implying that at 8x you can get a multi-GPU mode working.
>
> At minimum, nVidia needs to clean up the text and explanations in these
> dialogs. It's a mess. Can someone explain what these warnings actually
> mean?
>
> Can someone explain what are the implications of turning off multi-GPU
> performance modes? If I want 8x antialiasing for visual quality, is there
> any way to get both GPUs on the 7950 working towards rendering a scene?
> Maybe in this case I would be forced to select one of the alternate frame
> rendering modes 1 or 2?
>

There are few (if any) games that can handle 8X FSAA at any resolution
with a 7950GT. It is no longer offered (unless forced) since it is not
desirable or practicable.

Remember that anti-aliasing is a substitute for increased resolutions,
you should try to increase resolution first, then apply filtering such
as FSAA.

Every application handles FSAA differently, from Half Life (which looks
fantastic with it) to BF2 (which needs FSAA and other additional
methods) to Unreal Tournament, which only tolerates it if forced.

If you find that in your application 4X FSAA isn't cutting it for you
visually, you should experiment with different modes, super sampling and
its derivatives RG and OG and MS. These additional modes greatly add to
the IQ of the rendered scene, based on the engine and specific game. For
example transparency AA in HL2, a must in those levels populated with
fencing.

Along with FSAA, mipmapping and anisotropic filtering are a necessity,
and LOD control when set properly creates the best image possible with
any given hardware, eliminating all visual artifacts.

I recommend nhancer, it's exactly what you need for your both your IQ's.

http://www.nhancer.com

Will
December 24th 07, 03:29 AM
"Mr.E Solved!" > wrote in message
...
> There are few (if any) games that can handle 8X FSAA at any resolution
> with a 7950GT. It is no longer offered (unless forced) since it is not
> desirable or practicable.

But then why does the very latest driver for Windows XP announce, when you
switch away from 8x FSAA, that Multi-GPU visual quality is highest when set
to 8x FSAA? It is worded in a way that seems to discourage you from not
using 8x FSAA.

My only game is Microsoft Flight Simulator X, and I have antialiasing on in
the game settings as well as 8x FSAA forced in nVidia Control Panel for the
7950. I've experimented with 4X FSAA but it looks bad. I tried just now
to set the nVidia Control Panel antialiasing to "Let application decide" and
that seems to look better than 4x FSAA. Is that the recommended setting?

Which rendering mode do you think would give the best multi-GPU performance
with that game? Choices are split-frame rendering or alternate rendering
methods 1 and 2 (whatever those are).

I have all anistrophic filter settings and other nVidia Control Panel
settings on best quality settings.

--
Will


"Mr.E Solved!" > wrote in message
...
> Will wrote:
> > Starting about a year ago, nVidia modified its GEForce 7 drivers to
remove
> > the 8xS antaliasing mode, which was compatible with multi-GPU
performance.
> > Now you are forced to choose in the nVidia control panel between 4x and
8x.
> > 4x gives mediocre antialiasing. 8x gives a good visual result, but if
you
> > select 8x antialiasing you get a modal dialog warning you that this mode
is
> > incompatible with multi-GPU support. Why would nVidia put such an
awful
> > restriction into the drivers for this card? In effect, to get good
visual
> > qualities you have to cripple the card's potential performance? To
make a
> > confusing issue utterly unintelligible, if you then switch from 8x to 4x
> > antialiasing, you get a different modal dialog that warns you that going
> > from 8x to 4x will compromise the best "multi-GPU performance". This
> > directly contradicts the earlier dialog when going from 4x to 8x, by
> > implying that at 8x you can get a multi-GPU mode working.
> >
> > At minimum, nVidia needs to clean up the text and explanations in these
> > dialogs. It's a mess. Can someone explain what these warnings
actually
> > mean?
> >
> > Can someone explain what are the implications of turning off multi-GPU
> > performance modes? If I want 8x antialiasing for visual quality, is
there
> > any way to get both GPUs on the 7950 working towards rendering a scene?
> > Maybe in this case I would be forced to select one of the alternate
frame
> > rendering modes 1 or 2?
> >
>
> There are few (if any) games that can handle 8X FSAA at any resolution
> with a 7950GT. It is no longer offered (unless forced) since it is not
> desirable or practicable.
>
> Remember that anti-aliasing is a substitute for increased resolutions,
> you should try to increase resolution first, then apply filtering such
> as FSAA.
>
> Every application handles FSAA differently, from Half Life (which looks
> fantastic with it) to BF2 (which needs FSAA and other additional
> methods) to Unreal Tournament, which only tolerates it if forced.
>
> If you find that in your application 4X FSAA isn't cutting it for you
> visually, you should experiment with different modes, super sampling and
> its derivatives RG and OG and MS. These additional modes greatly add to
> the IQ of the rendered scene, based on the engine and specific game. For
> example transparency AA in HL2, a must in those levels populated with
> fencing.
>
> Along with FSAA, mipmapping and anisotropic filtering are a necessity,
> and LOD control when set properly creates the best image possible with
> any given hardware, eliminating all visual artifacts.
>
> I recommend nhancer, it's exactly what you need for your both your IQ's.
>
> http://www.nhancer.com
>
>
>
>
>

Mr.E Solved!
December 24th 07, 07:10 AM
Will wrote:


> But then why does the very latest driver for Windows XP announce, when you
> switch away from 8x FSAA, that Multi-GPU visual quality is highest when set
> to 8x FSAA? It is worded in a way that seems to discourage you from not
> using 8x FSAA.

Who can say. Perhaps it is an SLI accommodation. Unless you are using
crossfire and that's why you keep calling it "Multi-GPU"

> My only game is Microsoft Flight Simulator X, and I have antialiasing on in
> the game settings as well as 8x FSAA forced in nVidia Control Panel for the
> 7950. I've experimented with 4X FSAA but it looks bad. I tried just now
> to set the nVidia Control Panel antialiasing to "Let application decide" and
> that seems to look better than 4x FSAA. Is that the recommended setting?

FSAA in FSX (and 9) is poorly implemented, the standard approach is to
force FSAA from the driver, ignoring the applications FSAA setting
(leave it off).

However things change, patches etc. See what works best for you. But
start there.


> Which rendering mode do you think would give the best multi-GPU performance
> with that game? Choices are split-frame rendering or alternate rendering
> methods 1 and 2 (whatever those are).

Easy: see what mode works best for you. It won't break.


> I have all anistrophic filter settings and other nVidia Control Panel
> settings on best quality settings.

Those settings are qualitative, not quantitative, for complete filtering
control you need to specify amounts, FSX suffers from heavy texture
aliasing (terrain, trees, structures) and 16X aniso and trilinear
mipmapping is a must. Create a FSX profile from the control panel if one
does not already exist for this advanced method of configuration or you
can use a third party program to force these settings. Rivatuner,
nhancer, powerstrip, etc.

You are going to have to painstakingly check every setting and mode to
see which works and looks best on your system. FSX is atypical in many
ways. Good luck!