DX10 vs DX11 video - Is this even a good comparison?

DtD · Post by **DtD** » Mon Dec 14, 2009 3:03 am

iirc DX10 had geometry shaders, which this apparently uses, so I am kinda confused why they are touting this as super DX11. I am not proposing a DX10/11 driver for Irrlicht, but a (non-programmer) friend sent me this video.

http://www.youtube.com/watch?v=PR40GwRtFyw#t=1m45s
So basically, I am just curious what is happening here and what kinds of comments you guys have here.

~DtD

ArakisTheKitsune · Post by **ArakisTheKitsune** » Mon Dec 14, 2009 3:23 am

I don't know much about DirectX but correct me if I am wrong. He demonstrates difference between DX10 and DX11 but to me it looks like he is just switching between 3D models. This looks to me like: I create window using Irrlicht and under DX8. And then I would load a fairy model. And then I load some Hi quality 3D model and call that DX9 mode

As I said correct me if I am wrong ^^" but that looks like from my point of view.

Lonesome Ducky · Post by **Lonesome Ducky** » Mon Dec 14, 2009 3:38 am

DirectX 11 shows off hardware tessellation

DtD · Post by **DtD** » Mon Dec 14, 2009 3:39 pm

@Arakis
Like Ducky said, I believe it is hardware tessellation not different models.

@Ducky
Before I thought that hardware tessellation was in DX10 too, but I just checked again and I guess it isn't. So I guess this is a decent comparison. Although with DX11 cards still new and rare, I doubt we will be seeing many games using this technology soon.

One thing I am wondering is why we can't just load really high poly stuff instead of tessellating it in hardware.

~DtD

Halifax · Post by **Halifax** » Mon Dec 14, 2009 3:48 pm

DtD wrote: One thing I am wondering is why we can't just load really high poly stuff instead of tessellating it in hardware.

Because that increases the bandwidth that you must use. The use of tessellation in hardware overcomes this problem by instead using the computational power of the GPU to procedurally generate meshes with higher poly counts through the use of either bezier patches or the subdivision of conventional polygons.

And DX10 doesn't have tessellation, but it does have geometry shaders (like DX11) that could be programmed to perform tessellation, but the performance will no where near reach the performance of the fixed function tessellator on a DX11 GPU.

And games are already starting to take advantage of DX11. The first one being Dirt 2 by Codemasters and then the Frostbite Engine (I don't know the company) albeit a small market for consumers, thus you will see many games support DX9 as well, but put extra graphical whistles on their DX11 version.

yamashi · Post by **yamashi** » Tue Dec 15, 2009 10:11 pm

Hardware tesslation was already present in Dx10.1 so I don't see why everybody is getting excited about Dx11... Dx11 is just Dx10.1 with a multi-threaded architecture to me...

DtD · Post by **DtD** » Tue Dec 15, 2009 10:49 pm

And I remember reading somewhere that DX9 and 10 cards will be able to take advantage of the multithreading anyway

"Parts of the new API such as multi-threaded resource handling can be supported on Direct3D 9/10/10.1-class hardware." {Wikipedia}

~DtD

lostclimategames · Post by **lostclimategames** » Tue Dec 15, 2009 11:07 pm

i just love the guy reviewing it... lol "they didnt do much with the rocks" and "ropes in dx 11 are much better than 10" as if ms specifically was working on effects for those assets

Virion · Post by **Virion** » Wed Dec 16, 2009 1:48 am

imo DX11 is more about optimization.
by the way WHERE IS OPENGL 3.2 DEMO?!!!!

they should make some demo not just releasing the spec

DtD · Post by **DtD** » Wed Dec 16, 2009 2:45 am

@lostclimategames
lol, yeah. The guy had no idea what he was talking about.

@Virion
Yeah, that is how I had seen it before. (And still do.)

~DtD

Halifax · Post by **Halifax** » Wed Dec 16, 2009 3:57 am

Hardware tessellation was NOT present in DX10.1 class hardware. DX11 adds to the specification a necessity of a hardware fixed-function tessellator. You're probably thinking about doing tessellation in a geometry shader which I already discussed as being far from optimal. The geometry shader is not meant for such a thing.

Yes DX11 applies to DX9, 10, and 11 class hardware. The multi-threading architecture is by far a great improvement that allows the programmer to take advantage of things that people have being doing with the PS3 and 360, and that is allowing the user to cache graphics commands in lists. The driver captures the list at the driver level, thus it is not necessary for the hardware to be DX11 class.

I like what DX11 is. The only thing that I would like to see them add is the "GPU pointer addresses" that nVidia has already provided to OpenGL through extensions. Then even more optimizations could be taken advantage of.