ATI Radeon 9700 Dissected

Bender writes "The guys who laid out the future of real-time graphics a while back have now dissected ATI's Radeon 9700 chip. Their analysis breaks down performance into multiple components--fill rate, occlusion detection, pixel shaders, vertex shaders, antialiasing--and tests each one synthetically before moving on to the usual application tests like SPECviewperf and UT 2003. You can see exactly how this chip advances the state of the art in graphics, piece by piece. Interesting stuff."

Comments

Re:Enthusiasm for procedural shaders

[Crag]

It's not just the pixelation or blurring that procedural shaders solve. Combined with other techniques such as bump and environment mapping, surfaces can be given depth without increasing the poly count. A texture can be be made to look like water without transmitting wave information to the video card. Just send a function.

The combination of pixel and vertex shaders allows stunning effects like flag that flaps in the wind and still casts the right shadows, and it's all done on the card (an example I stole from an NVidia presentation).

It's no cure-all, but it is another large step forward.

Fun facts about NVIDIA's drivers...

[Lethyos]

NVIDIA uses the same codebase for ther Windows, Mac OS ?, and Linux drivers. This same codebase will also be used for their FreeBSD drivers to come. Their unified driver architecture ensures that every platform the card runs on gets the latest version of the code and can take advantage of each card's features. So this is definitely a few notches above ATI who won't even produce drivers for my platform, let alone release full specifications to the public to write them.

As for the complaint that NVIDIA is no better than ATI because of a binary driver release: that is not NVIDIA's fault. NVIDIA tries to make as much of their driver open source as possible (which is kind of a necessity because of the plethora of kernel configurations out there). However, the closed-source portions are kept closed because of SGI's patents on OpenGL. Assign blame where blame is due, please.

Re:I found its weakness!

[SuiteSisterMary]

Actually, it does matter with more FPS. Don't compare it to film, because even though they both use the term 'frame' they mean different things.

A 24 fps film means that each frame is recording 1/24th of a second. That means that if an object being filmed is moving fast enough, the frame will have motion blur. When strung together with the other frames, this will give the illusion of smooth movement. A 24 fps 3d engine, however, means that you have 24 static shots. There's no transition from point to point, unless you wind up rendering said inbetween shots. Or, put another way, a 5 fps film of a hand waving in front of the camera will produce five frames full of motion-blurred hand, which, when played, will look relatively smooth. A 5 FPS render, however, will have five static shots of a hand sitting motionless in space, and when played, the hand will appear to 'teleport' from spot to spot to spot.

Or, put another way, record that hand with a standard camera shooting at five 'frames per second' not 'several frames, each 1/5th of a second exposure' and then string the negatives into a film reel, splicing in copies to make the whole thing last one second.

This is one of the reasons, I always thought, that 3dFX was trying to get their T-buffer out into the world, becuase then, yes, if you could LOCK the rendering at 30 FPS, and throw in motion and acceleration blur, it would still look better than a card rendering the exact same thing at 300 FPS.