Quick question: GF3 and pixel shader support

[Johnny Rotten]

GF3 has hardware support for PS1.1, 1.2, and 1.3 correct?

 

[Dave Baumann]

GF3
GF4 (Although I can't remember if there was some queries over the support of PS1.2 on GF4)

 

[MatiasZ]

wow i didn´t know this list existed... great table 8)

edit: how come the GF3 appears as "Filtering per texture unit = Bilinear" while GF1 appears as Trilinear??

 

[Zeross]

edit: how come the GF3 appears as "Filtering per texture unit = Bilinear" while GF1 appears as Trilinear??

Starting with the NV15 Nvidia has chosen to "cut" the only texture unit of the NV10 in two. The NV10 texture unit was able to fetch 8 samples from two succesive mipmaps, which allowed it to do single cycle trilinear. On the other hand each of NV15 texture unit was only able to fetch 4 samples. But Nvidia judged back then that 4 bilinear filtered, dual textured pixels / cycle was morte important than 4 trilinear filtered, single textured pixels / cycle.

 

[oddfellow]

Wasn't NV20 supposed to support ps1.3, but it was allways broken? (and disabled in the drivers)

 

[Cryect]

Heh, I wish that list had what OpenGL extras they all support. Damn ATI doesn't seem to like listing that information on their website for older generations (annoying when trying to ensure something works on a wide range of cards and you don't have all the older cards you would like it to potentially work on and even if you do be preferred if you know in advance what code will work on).

 

[Zeross]

Heh, I wish that list had what OpenGL extras they all support. Damn ATI doesn't seem to like listing that information on their website for older generations (annoying when trying to ensure something works on a wide range of cards and you don't have all the older cards you would like it to potentially work on and even if you do be preferred if you know in advance what code will work on).

Maybe this can help you.

 

[KimB]

Wasn't NV20 supposed to support ps1.3, but it was allways broken? (and disabled in the drivers)

There was no support for PS 1.2 or PS 1.3 until the NV25. Whether or not it was bugs on-chip that disabled the features required to support PS 1.2-1.3 would be something internal to nVidia. The best you could ever glean about this would be rumors, but I personally doubt it would be true.

If it were true, then the bug would not have been realized until the release of the NV20, but I believe DX8, and the inability to support the features for PS 1.3 would have required a new DirectX update that had a lower pixel shader version that exposes only the features the NV20 did use.

Regardless, you're probably mixing up another issue that nVidia had. Apparently the very first revision of the GeForce3 (which sold in very small quantities) did not have 3D texture support enabled due to a bug on the chip. This was fixed with the next revision.

 

[Cryect]

Heh, I wish that list had what OpenGL extras they all support. Damn ATI doesn't seem to like listing that information on their website for older generations (annoying when trying to ensure something works on a wide range of cards and you don't have all the older cards you would like it to potentially work on and even if you do be preferred if you know in advance what code will work on).

Maybe this can help you.

Ahh cool ^_^

Wish I knew about that before.

Regardless, you're probably mixing up another issue that nVidia had. Apparently the very first revision of the GeForce3 (which sold in very small quantities) did not have 3D texture support enabled due to a bug on the chip. This was fixed with the next revision.

Eek, I didn't see the news on that one back then. Though most games don't really use 3d textures (which makes sense considering performance of most of them out there).

 

[DeanoC]

Wasn't NV20 supposed to support ps1.3, but it was allways broken? (and disabled in the drivers)

In fact its argueable the NV20 didn't fully support ps1.1! The specification of ps1.1. is 8 vector and 8 coissue scalar ops, NV20 only actually supported 8 vector and 7 coissue scalar ops. Some perfectly legal shaders don't run... The exact cause is trying to coissue in the last instruction.

Still as it was the first and most successful ps1.1. device, everybody just worked around it.

 

[Reverend]

Actually, a lot of things are argueable and not quite what it seems (regardless of what is on the Internet).

Presumably, of course.

 

[Unknown Soldier]

The original GF3 came out with PS/VS1.1 support(DX8.0). I think the GF3 TI had support for PS/VS1.2(DX8.1) and the GF4 comes with PS/VS1.4(DX8.1).

I could be wrong though.

Ok.. looks like I am wrong(according to Dave's info).

Just a question Dave. When the original GF3 was release I know it had PS/VS1.1 and supported DX8.0 and when the GF3TI series was released I read that the VS was fixed to 1.2 and that it could run DX8.1. At least that's what I've always though these last few years(mainly cussing meself for not waiting for the TI Series).

US

 

[MatiasZ]

edit: how come the GF3 appears as "Filtering per texture unit = Bilinear" while GF1 appears as Trilinear??

Starting with the NV15 Nvidia has chosen to "cut" the only texture unit of the NV10 in two. The NV10 texture unit was able to fetch 8 samples from two succesive mipmaps, which allowed it to do single cycle trilinear. On the other hand each of NV15 texture unit was only able to fetch 4 samples. But Nvidia judged back then that 4 bilinear filtered, dual textured pixels / cycle was morte important than 4 trilinear filtered, single textured pixels / cycle.

thanks that pretty much explains it 8)

 

[Unknown Soldier]

Ok I thought I was right. The GF3 TI Series has DX8.1 support PS1.2.

Oops I go back to PS1.2 support with OGL 1.3 Support.

http://www.amdmb.com/article-display.php?ArticleID=153&PageID=2

Microsoft DirectX 8.1 and OpenGL 1.3 Optimizations and Support
Delivers the best performance and guarantees compatibility with all current and future 3D applications and games.

US

 

[oddfellow]

Wasn't NV20 supposed to support ps1.3, but it was allways broken? (and disabled in the drivers)

Ah well, looks like another internet rumour that I should've ignored

 

[Dave Baumann]

Ok I thought I was right. The GF3 TI Series has DX8.1 support PS1.2.

GF3 Ti is nothing more than a speed binned NV20, with no silicon changes. Driver claiming "support" for an API doesn't not necessarily equate to being fully compliant with its capabilities.

 

[Tim Murray]

Ok I thought I was right. The GF3 TI Series has DX8.1 support PS1.2.

GF3 Ti is nothing more than a speed binned NV20, with no silicon changes. Driver claiming "support" for an API doesn't not necessarily equate to being fully compliant with its capabilities.

uhhh... is there even a PS1.2?

 

[Ostsol]

Ok I thought I was right. The GF3 TI Series has DX8.1 support PS1.2.

GF3 Ti is nothing more than a speed binned NV20, with no silicon changes. Driver claiming "support" for an API doesn't not necessarily equate to being fully compliant with its capabilities.

uhhh... is there even a PS1.2?

Yep. It is missing one instruction from PS1.3. I cannot find any other difference.

 

[Reverend]

wow i didn´t know this list existed... great table 8)

Which reminds me : Dave, when is this gonna be on the nav menu?

[edit : )

 

[Dave Baumann]

uhhh... is there even a PS1.2?

Yep. It is missing one instruction from PS1.3. I cannot find any other difference.

Missing "texm3x2depth"

Why reminds me : Dave, when is this gonna be on the nav menu?

[edit : )

I assume that was because you've since found it on the nav menu?