NVIDIA GeForce 6800 Ultra: The Next Step Forward
by Derek Wilson on April 14, 2004 8:42 AM EST- Posted in
- GPUs
What's new in DX 9.0c
This year the latest in the DirectX API is getting a bit of a face lift. The new feature in DirectX 9.0c is the inclusion of Pixel Shader and Vertex Shader 3.0. Rather than calling this DirectX 9.1, Microsoft opted to go for a more "incremental" looking update. This can end up being a little misleading because whereas the 'a' and 'b' revisions mostly extended and tweaked functionality, the 'c' revision adds abilities that are absent from its predecessors.
Pixel Shader 3.0 (PS3.0) allows shader programs of over 65,000 lines and includes dynamic flow control (branching). This revision also requires that compliant hardware offer 4 Multiple Render Targets (MRT's allow shaders to draw to more than one location in memory at a time), full 32-bit floating point precision, shader antialiasing, and a total of ten texture coordinate inputs per pixel.
The main advantage here is the ability for developers to write longer, more complex, shader programs that run more efficiently. The flow control will give developers the freedom to write more intuitive code without sacrificing efficiency. Branching allows a shader program the expanded ability to make decisions based on its current state and inputs. Rather than having to run multiple shaders that do different things on different groups of pixels, developers can have a single shader handle an entire object and take care of all its shading needs. Our example of choice will be shading a tree: one shader can handle rendering the dynamics of each leaf, smooth new branches near the top, rugged old bark on the trunk, and dirty roots protruding from the soil.
Vertex Shader 3.0 extends its flow control ability by adding if/then/else statements and including the ability to call subroutines in shader programs. The instruction limit on VS3.0 is also extended to over 65000. Vertex textures are also supported, allowing more dynamic manipulation of vertices. This will get even more exciting when we make our way into the next DirectX revision which will allow for dynamic creation of vertices (think very cool particle systems and hardware morphing of geometry).
One of the coolest things that VS3.0 offers is something called instancing. This functionality can remove a lot of the overhead created by including multiple objects based on the same 3d model (these objects are called instances). Currently, the geometry for every model in the scene needs to be setup and sent to the GPU for rendering, but in the future developers can create as many instances of one model as they want from one vertex stream. These instances can be translated and manipulated by the vertex shader in order to add "individuality" to each instance of the model. To continue with our previous example, a developer can create a whole forest of trees from the vertex stream of one model. This takes pressure off of the CPU and the bus (less data is processed and sent to the GPU).
Now that we've seen what developers are looking at with DirectX 9.0c, let's take a look at how NVIDIA plans to bring these features to the world.
Facebook
Twitter
RSS
77 Comments
View All Comments
Regs - Wednesday, April 14, 2004 - link
Wow, very impressive. Yet very costly. I'm very displeased with the power requirments however. I'm also hoping newer drivers will boost performance even more in games like Far cry. I was hoping to see at least 60 FPS @ 1280x1024 w/ 4x/8x. Even though it's not really needed for such a game and might be over kill, however It would of knocked me off my feet enough where I could over look the PSU requirement. But ripping my system apart yet again for just a video card seems unreasonable for the asking price of 400-500 dollars.Verdant - Wednesday, April 14, 2004 - link
i don't think the power issue is as big as some make it out to be, some review sites used a 350 W psu, and two connectors on the same lead and had no problems under loaddragonballgtz - Wednesday, April 14, 2004 - link
I can't wait till December when I build me a new computer and use this card. But maybe by then the PCI-E version.DerekWilson - Wednesday, April 14, 2004 - link
#11 you are correct ... i seem to have lost an image somewhere ... i'll try to get that back up. sorry about that.RyanVM - Wednesday, April 14, 2004 - link
Just so you guys know, Damage (Tech Report) actually used a watt meter to determine the power consumption of the 6800. Turns out it's not much higher than a 5950.Also, it makes me cry that my poor 9700Pro is getting more than doubled up in a lot of the benchmarks :(
CrystalBay - Wednesday, April 14, 2004 - link
Hi Derek, What kind of voltage fluctuations were you seeing... just kinda curious about the PSU...PrinceGaz - Wednesday, April 14, 2004 - link
A couple of comments so far...page 6 "Again, the antialiasing done in this unit is rotated grid multisample" - nVidia used an ordered grid before, only ATI previously used the superior rotated grid.
page 8 - both pictures are the same, I think the link for the 4xAA one needs changing :)
Can't wait to get to the rest :)
ZobarStyl - Wednesday, April 14, 2004 - link
dang ive got a 450W...sigh. That power consumption is really gonna kill the upgradability of this card (but then again the x800 is slated for double molex as well). I know it's a bit strange but I'd like to see which of these cards (top end ones) can provide the best dual-screen capability...any GPU worth its salt comes with dual screen capabilities and my dually config needs a new vid card and I dont even know where to look for that...and as for cost...these cards blow away 9800XT's and 5950's...it wont be 3-4 fps above the other that makes me pick between a x800 and a 6800...it will be the price. Jeez, what are they slated to hit the market at, 450?
Icewind - Wednesday, April 14, 2004 - link
Upgrade my PSU? I think not Nvidia! Lets see what you got AtiLoneWolf15 - Wednesday, April 14, 2004 - link
It looks like NVidia has listened to its customer base. I'm particularly interested in the hardware MPEG 1/2/4 encoder/decoder.Even so, I don't run anything that comes close to maxing my Sapphire Radeon 9700, so I don't think I'll buy a new card any time soon. I bought that card as a "future-proof" card like this one is, and guess what? The two games I wanted to play with it have not been released yet (HL2 and Doom3 of course), and who knows when they will be? At the time, Carmack and the programmers for Valve screamed that this would be the card to get for these games. Now they're saying different things. I don't game enough any more to justify top-end cards; frankly, and All-In-Wonder 9600XT would probably be the best current card for me, replacing the 9700 and my TV Wonder PCI.