SM 3.0

[mart]

The difference between SM 2.0 and 3.0:

2.0 2.A 3.0
Shader Precision 24 24 32
Prediction of instructions no yes yes
temporary registers 12 22 32
constant registers 32 32 224
dynamic control no no yes

constant registers: input values of the developer
dynamic control: also called Dynamic Branching - a shader can loop different parts of a shader (like repeat program part 3 while i < 6), can start a shader part if a value is ok (if i == 0 {...}) or stop the shader at any time (if pixelcolor == black --&#62; stop)

Pixel Shader programs do know the x/y position of a pixel.
3.0 shaders can load textures,and so it is possible, that some physics can be done at the GPU. (If the effect is only graphical, and not important for the game in any other way - so no influence on the game) Examples are damages at a car (sheet metal-harm) or the waves at a beach...

GPU&#39;s of NV 40 series are the only ones which can mix new computed floatingpoint-pixels with pixelcolors in the gpu ram. So they are the only ones which can provide HDR fully in Hardware. X800 series emulates the HDR with Pixelshaderprograms and dynamic computed textures. (The user won&#39;t see any difference)


EDIT Pics of HDR at my review of 6800 LE center (http://forums.gamershell.com/index.php?act=ST&f=48&t=10549)

[Sepht]

your going to argue with me about this aren&#39;t you?

Also care to cite your source?

"Previous generation graphics processors from NVIDIA didn’t support information output from the pixel shader to a few buffers simultaneously (Multiple Render Targets) and data rendering into a buffer in floating-point representation (FP Render Target). ATI RADEON “R3xx” graphics chips family supported these features from the very beginning, which made an advantageous difference from NVIDIA’s solutions." -XbitLabs

[mart]

Originally posted by Sepht@Mar 6 2005, 03:28 PM
your going to argue with me about this aren&#39;t you?

Also care to cite your source?

"Previous generation graphics processors from NVIDIA didn’t support information output from the pixel shader to a few buffers simultaneously (Multiple Render Targets) and data rendering into a buffer in floating-point representation (FP Render Target). ATI RADEON “R3xx” graphics chips family supported these features from the very beginning, which made an advantageous difference from NVIDIA’s solutions." -XbitLabs
argue: Sir, no Sir.

sources: sorry that i forget --&#62; PCGH and TomsHardwareGuide

[Sepht]

No, its not because of varied sources.
MRT allows for about same style effect, true floating point per pixel lighting.
Its implemented differently though, but you can still get True HW HDR out of both of them.

The thing is, Your trying to merge SM3.0 and HDR, there is no connection.
Nvidia implemented HPDR/OpenEXR to manage their HDR, and also seperatly SM3.0

If you read up on SM3.0
I.E. Microsoft/nvidia&#39;s page
http://www.microsoft.com/whdc/winhec/partn...l30_NVIDIA.mspx (http://www.microsoft.com/whdc/winhec/partners/shadermodel30_NVIDIA.mspx)

You&#39;ll see its pure performance differances. They say so themselves.

HardOCP investigated it too.
http://www.hardocp.com/article.html?art=NjA5


btw, "Geometry Instancing" is also supported by ATi R3xx. I remember it being mentioned on a driver readme a while back

[CpTn_lAw]

SM3.0 makes no visual difference for the moment. It allows the GPU to calculate very very faster than with SM2.0, but gives the same render. Now, when they release games that are fully based on the SM3.0 technology, they will be able to make new lighting and shadows and bump mapping and normal mapping that will be calculate very fast. SM3.0 permits it.

[Strawberry knight]

Originally posted by CpTn_lAw@Mar 6 2005, 07:08 PM
SM3.0 makes no visual difference for the moment.
Did you even play any game that supports it before saying that?

Lord of the rings: Battle for the middle earth
Stalker: Shadows of Chernobyl
Splinter Cell 3
Tiger Woods 2005
Vampire: Bloodlines
Tiger Woods 2005
Madden 2005
Driver 3.0
Grafan
Medal of Honor: Pacific Assault
Patched Painkiller
Not sure about HL2, but it has SM3 support
And patched Far cry.

[Sepht]

sorry grim, but it doesn&#39;t.

SM3.0 is just a set of performance increases that could allow the usage of more advanced things that could be done in SM2.0(a)(B)

[CpTn_lAw]

I&#39;ve got a 6800GT that supports it, Grimreapper. So i&#39;ve got no reason to say it&#39;s teahat. But in Far cry it only gives me 10 fps more, in hl2 i&#39;m always @ 45-60fps, in battle for the middle earth i see no bump mapping, and S.T.A.L.K.E.R. is not yet out. (please god, make stalker ship tomorow&#33; :crybaby: :crybaby: ) Medal of honor pacific assault looks great but i can&#39;t afford it, til one month, and i want brothers in arms wishing it will have SM3.0 to run hypersmooth...
I&#39;ve patched Painkiller but it was given by a friend and i don&#39;t have the cd to play the patched version

[Kacperski]

Some effects are just a pain in the ass (not to mention slow) with ps 2.0 so they weren&#39;t used till 3.0.
If you see difference in farcry and other it&#39;s just that.