NVIDIA G80: Architecture and GPU Analysis - Page 1
Published on 8th Nov 2006, written by Rys for Consumer Graphics - Last updated: 25th Apr 2007
We might as well take these first words in our look at NVIDIA's G80 graphics processor, the first GPU from any consumer graphics vendor that supports Windows Vista's Direct3D 10 (D3D10) component, to let you know that this piece marks the beginnings of Beyond3D doing things a little bit differently in terms of brand new GPU analysis. From now on we'll be splitting things up three ways, focussing separately on the architecture, its possible image quality and lastly its performance, possibly with other orbiting satellite articles depending on other Cool Stuff that it can do, enables or tickles us with.
That means there'll start to be three separate articles for you to digest, possibly not all coming on the same day depending on what it's all about, but always following each other in short order. That lets us focus on what Beyond3D's famous for first of all, before we go nuts on the other good stuff, allowing time for things to settle down and discussion to form, before the next piece of the puzzle slides into view. Of course each piece will be a complement of all the others, with the right references back and forth, so Arch will reference IQ will reference Perf will reference Arch, and so on and so forth. So even if we just rock out with Arch on launch day, as we are today, you'll still get an idea of the other two. Hope that's cool, let us know what you think since we think it offers more advantages than not to all concerned, authors, downtrodden publisher and readers alike.
We should also drop the bomb that we'll also be directly comparing cross-IHV in the future (and for G80), where appropriate, when constructing any piece here at Beyond3D. You'll see AMD and NVIDIA GPUs go toe-to-toe, directly in the same piece be it for arch, IQ, perf (or whatever) reasons, whenever it makes sense to do so. So a couple of shifts in how you'll see us do what we do, and definitely for the better. The pieces as a whole will represent a stronger final product than Beyond3D's been able to produce in the past, and it's that which has driven the change. Gotta keep it fresh and focussed lest the other guys catch up, right? Thus without further ado, we happily present our first stab at the new way of doing things; our NVIDIA G80 Architecture and GPU Analysis.
NVIDIA G80: Architecture and GPU Analysis
Four years and 400 million dollars in the making, NVIDIA G80 represents for the company their first brand new architecture with arguably no strong ties to anything they've ever built before. Almost entirely brand new as far as 3D functions are concerned, and designed as the flagship of their 8-series GeForce product line, their new architecture is squarely a D3D10 part but with serious D3D9 performance and image quality considerations. One doesn't beget the other in the world of programmable shading, and NVIDIA seem to want to hit the ground running. Arguably the masters of the compromise, of which all modern 3D rendering is anyway, the Cali-based graphics company has no problems loving some parts of the chip less than others, in the pursuit of the best product for the market they're addressing.
D3D10 makes that a bit more difficult, though. Any D3D10 accelerator must support all base API features without any exceptions, developers requiring a level playing field in order to further the PC as a platform and fruitful playground for graphics application development, be they games or GPGPU or the next generation of DCC tools, or whatever the world feels like building. Performance is the differentiator with D3D10, not the feature check list. There's no caps bit minefield to navigate, nor a base feature to be waived. So the big new inflection point probably should have been a big hint.
So what have NVIDIA come up with for D3D10? We know that dictates such features as support for geometry shading, constant buffers, unified shading instruction set, FP32 calculations throughout the entire pipeline, support for non-linear colour spaces in hardware and much much more, but how did they build it? Well who
really knows as far as D3D10 goes in depth, because NVIDIA,
ever the comedians, decided now is not the time for a driver for such endeavours! But nevermind. Being Beyond3D we dug deep, pushing the hardware around as is our wont, making it do naughty things under D3D9 in order to better understand the silicon under the big-ass hood.
We made the trip to the recent Editor's Day, got the skinny, grabbed the board and fled back to base. Now's the time to let you see what G80, mostly in the form of GeForce 8800 GTX, is all about from an architecture perspective. Leaked slides from Chinese websites will only get you so far. For the rest you need this. We look at the chip itself in physical form, then we examine the architecture with a walk across the GPU from front to back (mostly), so onwards we go.