Doom3 + ATI radeon family cards, up to X800..

[Keanu]

I've posted this as a reply to a review, and in the doom forum.
It's not new.. But easy to miss.

If you own an excellent radeon card and wish it ran faster
and better with Doom3; You can start by getting the ATI
Catalyst beta 4.9 HOTFIX.. It works rock solid and improves
the framerate quite a bit.

But the last part really makes doom3 smooth:
In case you missed the tweak. Here it is in ZIP format.
http://alexharis37.free.fr/doom/humusd3atitweak.zip
It's some sort of hotfix for the pixel shader to be ATI radeon friendly.
It does some float operations better, improves speed as well as
framerate. It also fixes specular glitches (pixies along some axis).
The speed gain to be expected is around 18%
Just unzip in your doom folder and it'll create a glprog within the base
folder with the now famous interaction.vfp by Humus, now working
for ATI... So this is not gonna break anything.

Hope it helps..
And people wondering about the game being dark should
dig informations on how to edit the DoomConfig.cfg and
up the gamma.... Brightness alone is washing the colours away.
r_gamma "1.4" is your friend !......USE IT !...

Hope it helps,
N³o

Looking around I found that Humus now works for ATI... CEWL !,
http://www.xbitlabs.com/news/other/display/20040808022148.html
Good for him.

Here for the records Humus own explanations for the increased speed:
-------------

Why would a single instruction on a 23-instruction shader make that much of a difference?

My theory is that it simply causes too much texture cache trashing. Remember that the specular component may vary a lot between
nearby pixels, so the access behavior will be quite erratic. Another thing could be that the number of texture accesses are so
high. There are seven different textures accessed in that shader. Now I don't have that much insight in how our hardware works,
maybe someone with more knowledge about that can fill me in. (sireric, where art thou? )

By the way, I tried it on my GeForce 6800, and could measure no performance difference. But, that doesn't mean much, as I'm pretty
heavily CPU-limited in the timedemo.

I was thinking that it wouldn't make much difference on nVidia, or perhaps be slower. I don't think Carmack just threw it in out of
pure habit, but he probably had a rational reason for it. I can see that it may not make much difference on a 6800, but I wouldn't
be surprised if the GF 5x00 series cards were much slower using math, they weren't that strong on floating point shaders as we all
know, so moving it to a texture lookup probably improved performance on that card, which I guess he used at the time he wrote that
shader.

Regardless, it looks like you're only exponentiating the x-component of the specular vector, while the LUT looks like it will

exponentiate >two components (2D texture lookup), so shouldn't you use 2 POW instructions?

No, both coordinates are the same as they are written by the DOT instruction. I would guess he has bound a Nx1 texture to that
unit.
Humus.
--------------- http://www.beyond3d.com/forum/viewtopic.php?p=342441#342441

 

[Sleepy]

I've posted this as a reply to a review, and in the doom forum.
It's not new.. But easy to miss.

If you own an excellent radeon card and wish it ran faster
and better with Doom3; You can start by getting the ATI
Catalyst beta 4.9 HOTFIX.. It works rock solid and improves
the framerate quite a bit.

I timedemo'd Doom 3 yesterday on my 9700 non-pro 290/290
with XP2400 and 512mb DDR. I run the game at 800x600 medium
settings and dynamic shadows disabled.
With the 4.8 betas Run 1 = 36.4
Run 2 = 41.3
With the Humus tweak Run 1 = 40.0
Run 2 = 42.4
With 4.9 betas and Humus Run 1 = 38.6
Run 2 = 42.0
So for me the Humus tweak raises the framerate by 1 fps and reduces the
stutter caused by loading /caching/whatever so the game feels smoother.
the 4.8s are slightly better than the 4.9s

But the last part really makes doom3 smooth:
In case you missed the tweak. Here it is in ZIP format.
http://alexharis37.free.fr/doom/humusd3atitweak.zip
It's some sort of hotfix for the pixel shader to be ATI radeon friendly.
It does some float operations better, improves speed as well as
framerate. It also fixes specular glitches (pixies along some axis).
The speed gain to be expected is around 18%
Just unzip in your doom folder and it'll create a glprog within the base
folder with the now famous interaction.vfp by Humus, now working
for ATI... So this is not gonna break anything.

Hope it helps..
And people wondering about the game being dark should
dig informations on how to edit the DoomConfig.cfg and
up the gamma.... Brightness alone is washing the colours away.
r_gamma "1.4" is your friend !......USE IT !...

Amen to the gamma tweak - none of the screenshots posted on the net
were taken with r_gamma "1" for sure. This is the only game Stevie Wonder
can play and win.

 

[Keanu]

Sleepy wrote in message ...

I timedemo'd Doom 3 yesterday on my 9700 non-pro 290/290
with XP2400 and 512mb DDR. I run the game at 800x600 medium
settings and dynamic shadows disabled.
With the 4.8 betas Run 1 = 36.4
Run 2 = 41.3
With the Humus tweak Run 1 = 40.0
Run 2 = 42.4
With 4.9 betas and Humus Run 1 = 38.6
Run 2 = 42.0
So for me the Humus tweak raises the framerate by 1 fps and reduces the
stutter caused by loading /caching/whatever so the game feels smoother.
the 4.8s are slightly better than the 4.9s

I did not know they had a 4.8beta, and thanks to you, I see it works well.

Now I think I know why some won't notice as much increase;
It's because you use MED quality.. I use HQ, and this enables a lot
ot 'shader' features in this 3D engine... The humus tweak then reveal
itself. I also run at 1024x768, because here 800x600 did not look as
good for some reason, and the framerate difference was not worth it.

Try running the game from a 16depth desktop if you are not already.
Of course that means the visual might drop in quality; But we all have
to chose to draw the line somewhere.

I think your framerate is already excellent... I run D3 around 35fps,
and I'm not considering one minute disabling features to gain fps.
But maybe you could see what the game looks at 1024x768x16.
Also you could try enabling anisotropy to 8 or even 16x in your config.
I bet the framerate drop will be insignificant...Thanks to Humus.
That's what happen here anyway.

I'm not sure if it's necessary to disable the dynamic shadows in
your case.. I don't want to make you feel bad; but that's one feature
you should try to keep enabled, as much as possible. It's so hot.
It shadows are too demanding for your system; Try this one:

seta r_useTurboShadow "1"
instead. It's not supposed to reduce the quality; But it's faster than
en more 'compatible' method used by D3.

And just to offer another TIP. Most installation will default to 60Hz
for 3D gaming.. But I think 60Hz sucks. You can fix this using a
supported refresh-rate with this parameter:
seta r_displayRefresh "70" for 70Hz.
Create and add this to autoexec.cfg if you don't have already.

Sorry I can't be of more help.
"Never give-up, never surrender." -Galaxyquest.
N³o

 

[who be dat?]

Interesting. Does this tweak only for Doom 3 or can we put it in every
OpenGL game folder, say Call of Duty perhaps? What folder do we put it in?
In other words, do we always put it in the same folder as the EXE or is
there a guideline for finding the folder to stick it in? Thanks!

Chris Smith

 

[Keanu]

Interesting. Does this tweak only for Doom 3 or can we put it in every
OpenGL game folder, say Call of Duty perhaps? What folder do we put it in?
In other words, do we always put it in the same folder as the EXE or is
there a guideline for finding the folder to stick it in? Thanks!

Chris Smith

Unfortunately not Chris.
This tweak applies only to Doom3, and uses specific engine design methods.
As I said earlier, Just unzip in your doom folder and it'll create a glprog within the base
folder with interaction.vfp.. Doom3 only will know what to do with it.

But if game designers are reading this forum and noticed how much this<
can affect pixel shader computations.. They shall improve their game design.
N³o