Geometry instancing

[Marsumane]

My question isnt a simple one (as always)
Basically how did ati figure out how their archetecture could do geometry instancing similar (or not) as the NV40?
How is each done and why can the R300 cores also do this? Why not the NV3X? Does anyone have any idea on how this is done on either archetecture, how they differ, what limits each have, and what beneficial do each yield in comparison to the competition?

 

[Marsumane]

Nobody... ?

 

[Jeff7181]

Can the R3xx do it? I thought it was only the R420.

 

[SickBeast]

Originally posted by: Jeff7181
Can the R3xx do it? I thought it was only the R420.

R300 can do Geometry Instancing and it will be enabled in the Catalyst 4.8 drivers.

It can't do SM2.0b though. I've been heavily researching this subject over the past few days, so ask if you have questions.

 

[Jeff7181]

Originally posted by: SickBeast

Originally posted by: Jeff7181
Can the R3xx do it? I thought it was only the R420.

R300 can do Geometry Instancing and it will be enabled in the Catalyst 4.8 drivers.

It can't do SM2.0b though. I've been heavily researching this subject over the past few days, so ask if you have questions.

Not that I don't trust you, but do you have a reliable source that says that? Cause the only article I read on it made it sound like it was an R420 feature that wouldn't extend back to the R3xx series.

 

[SickBeast]

Originally posted by: Jeff7181

Originally posted by: SickBeast

Originally posted by: Jeff7181
Can the R3xx do it? I thought it was only the R420.

R300 can do Geometry Instancing and it will be enabled in the Catalyst 4.8 drivers.

It can't do SM2.0b though. I've been heavily researching this subject over the past few days, so ask if you have questions.

Not that I don't trust you, but do you have a reliable source that says that? Cause the only article I read on it made it sound like it was an R420 feature that wouldn't extend back to the R3xx series.

Read this, I found it very interesting.

Instancing

The 2nd option is to have a R3xx or above graphics card (9500,9600,9700,9800) DirectX 9.0b, FarCry 1.2 and Catalyst 8.041. With this setup Geometry Instancing support is possible.

Thats right people, the NV40/SM3.0 isnt the only card/Shader Model that can provide instancing, any of ATI?s DX9 hardware supports this feature, in the words of some ATI employees (off the record) "even using DirectX9.0b"

The only R420 features that do not extend back to R300 are SM2.0b support and 3DC AFAIK.

 

[SickBeast]

Originally posted by: Jeff7181
I don't trust you

Read this if you want further proof

Enabling geometry (aka vertex) instancing is simple enough with this new version of Far Cry. For nVidia's GeForce 6800-based boards it can only be enabled by turning on the Shader Model 3.0 path (and thus cannot be tested in isolation as a feature), but for ATIs R3x0 and R420 boards it can be enabled by using the \r_GeomInstancing 1 switch.

I'm actually pretty disappointed; the R9800PRO only gained maybe 2% by enabling instancing. The only interesting thing is that instancing makes the vegetation look much nicer, and the 9800 didn't take a performance hit in doing so. They were even able to increase the amount of vegetation in the scene which is drawn using instancing with only maybe a 2% performance drop.

 

[nitromullet]

I'm actually pretty disappointed; the R9800PRO only gained maybe 2% by enabling instancing. The only interesting thing is that instancing makes the vegetation look much nicer, and the 9800 didn't take a performance hit in doing so. They were even able to increase the amount of vegetation in the scene which is drawn using instancing with only maybe a 2% performance drop

That is still pretty cool though. Anything that increases IQ and increases performance (even slightly) is a good thing.

 

[Marsumane]

Interesting Sickbeast. Thanks for the links.

 

[SickBeast]

Originally posted by: Marsumane
Interesting Sickbeast. Thanks for the links.

NP. :beer:

 

[nemesismk2]

ATI Catalyst drivers have a problem

ATI HAS A WHOPPER of a problem in the latest Catalyst drivers. The problem stems from Shader Model 2.0, 2.0b, 3.0, standards and MS certification of those standards. All drivers need to conform to standards, it is the reason standards are indeed standards, you adhere or you don't. If you don't, you are not compliant, and you lose the benefit of whatever said certifications bring.

That brings us to ATI again. It doesn't have SM3.0, and won't for a long time in the chip world, although when it is coming is a matter of debate. Nvidia has it now, that much is not in dispute. ATI said it could have done SM3.0 in the current generation of chips, but didn't think the trade off of die space versus performance was worth it. Nvidia did. It is a philosophical difference, and an economic decision, don't read anything more into it than that. Both firms are perfectly capable of releasing a SM3.0 chip if they think it is the right thing to do.

 

[Drayvn]

Thats why when they pass the test they will have Geometry Instancing off, and have it has an option to turn it on, its just up to the devs of games to have that option in game.