Archived

This topic is now archived and is closed to further replies.

Unsuspected

Do I need "Ti" for Cg?

Recommended Posts

JuNC    236
You won''t get full pixel shaders on either GeForce3 or 4 (Ti). You just get a sort of cut-down semi-programmable pipeline (using register combiners), which are still usable with Cg. To get full pixel shaders you''ll need one of the newer Radeons or a GeForceFX.

Share this post


Link to post
Share on other sites
JonnyQuest    331
quote:
Original post by JuNC
You won''t get full pixel shaders on either GeForce3 or 4 (Ti). You just get a sort of cut-down semi-programmable pipeline (using register combiners), which are still usable with Cg. To get full pixel shaders you''ll need one of the newer Radeons or a GeForceFX.

That''s not true. GeForce3 and 4 are in fact fully programmable, just not quite to the extent as the Radeon 8xxx/9xxx+ and GeForceFX



- JQ
#define NULL 1

Share this post


Link to post
Share on other sites
Guest Anonymous Poster   
Guest Anonymous Poster
Lets clear some of this up.

There are a few Pixel/Vertex shader versions out now.

Shaders 1.0 - Geforce3 Line of Video cards.
Shaders 1.3 - Geforce4 TI line of video cards.
Shaders 1.4 - Radeon 8500 Line of video cards.
Shaders 2.0 - Radeon 9500, 9700, 9800 Line of video cards.
Shaders 2.1 - Geforce FX line of video cards.


Now just FYI, the names of the nvidia Geforce line of video cards is based off the year which they come out, not the capabilities of the card itself. Which is why the Geforce4 MX is basically an overclocked Geforce2 MX.

Any card that supports Shaders 1.0 and up will be able to fully use shaders. However the newer versions of shaders offer alot more functionality than what is in the 1.0 standard.

Currently you can simulate Vertex Shaders in software mode and they run pretty fast, so you should be able to play around with these types of shaders on your MX video card. The same can not be said about pixel shaders which really can''t run in software mode because they are way too slow.

Share this post


Link to post
Share on other sites
JuNC    236
quote:

That''s not true. GeForce3 and 4 are in fact fully programmable, just not quite to the extent as the Radeon 8xxx/9xxx+ and GeForceFX



He was asking about pixel shaders and as such my post stands. I didn''t say you couldn''t get (pixel) programmability, just it wasn''t quite as flexible as the Radeon/FX.

Share this post


Link to post
Share on other sites
EvilDecl81    360
quote:
Original post by Anonymous Poster
Lets clear some of this up.

There are a few Pixel/Vertex shader versions out now.

Shaders 1.0 - Geforce3 Line of Video cards.
Shaders 1.3 - Geforce4 TI line of video cards.
Shaders 1.4 - Radeon 8500 Line of video cards.
Shaders 2.0 - Radeon 9500, 9700, 9800 Line of video cards.
Shaders 2.1 - Geforce FX line of video cards.


Now just FYI, the names of the nvidia Geforce line of video cards is based off the year which they come out, not the capabilities of the card itself. Which is why the Geforce4 MX is basically an overclocked Geforce2 MX.

Any card that supports Shaders 1.0 and up will be able to fully use shaders. However the newer versions of shaders offer alot more functionality than what is in the 1.0 standard.

Currently you can simulate Vertex Shaders in software mode and they run pretty fast, so you should be able to play around with these types of shaders on your MX video card. The same can not be said about pixel shaders which really can''t run in software mode because they are way too slow.




1.0 is a defunct standard for a hardware that never came out. Use 1.1 as baseline instead.


Share this post


Link to post
Share on other sites
JonnyQuest    331
quote:
Original post by JuNC He was asking about pixel shaders and as such my post stands. I didn''t say you couldn''t get (pixel) programmability, just it wasn''t quite as flexible as the Radeon/FX.
Nit-picking here, but you said one only has register combiners in GeForce 3/4Ti, etc. which isn''t true. But yeah, flexibility is definitely more limited.



- JQ
#define NULL 1

Share this post


Link to post
Share on other sites
DirectXXX    151
quote:
Original post by _Corrupt_
the gf4mx is nothing more than a renamed gf2.


wrong, gf4mx has many changes in whole pipe line. I cant remember my source. But im quite sure they have incremented and decremented some things. There is an article on net on GF4MX vs GF2

Share this post


Link to post
Share on other sites
Yann L    1802
quote:
Original post by JonnyQuest
Nit-picking here, but you said one only has register combiners in GeForce 3/4Ti, etc. which isn''t true.


Actually, for perpixel operation, it is true. All perpixel manipulations a GF3/4 can do, are either based on register combiners, or on texture shaders. The later ones can be seen as an extension to regcoms, that operate on texel fetch operations. You do not have fragment programmability (as with the FX), only fragment routing and combining, selecting from a set of predefined operations. OpenGL directly exposes this part of the hardware, while DirectX kind of disguises it into pseudo-programs, that are actually state-programs for the regcom/texshader pipeline.

That''s why, for example, you cannot feed a texel addressing operation with the results of a texel lookup on a GF3/4: the fixed regcom pipeline makes that impossible. It is however possible on an FX or Radeon 9x00.

As for vertex shaders, the GF3 is fully programmable (although more limited than newer cards, obviously).

Share this post


Link to post
Share on other sites