While NVIDIA's GeForce 9 series further optimized the unified shader architecture that debuted with the GeForce 8800 GTX (G80), there were no significant changes in the architecture. The flagship member of the series, the GeForce 9800 GTX packed the same number of stream processors as the original G80, with the die shrink to 65nm the biggest physical change. The other was an increase in transistors due to the integration of the much enhanced VP2 video processor engine for hardware accelerated HD playback into its G92 core.
Therefore, given the short life-cycle of the average GPU, it's about time NVIDIA came up with its next generation architecture. And the graphics industry leader has not only delivered an improved unified architecture, it has also revamped its naming scheme. Partly, this is due to the company reaching a natural limit to its four digit scheme with the GeForce 9000 series, while its products and their numerous prefixes were confusing some consumers. ATI has also recently simplified its product lineup starting with Radeon HD 3000 series so this move by NVIDIA to follow suit is not unexpected.
The new series, now simply known as the GeForce GTX 200, is based on a new unified shader architecture, though compared to the previous generation, this is an evolutionary step. Physically, the GTX 200 GPUs are the largest and most complex graphics processors designed by NVIDIA and are built by TSMC on a 65nm manufacturing process (still the same process technology unfortunately). With a transistor count of 1.4 billion, it is roughly double the 681 million on the first generation G80 architecture. This stat alone is staggering as it would be a very expensive part for NVIDIA and a possible concern of heat output.
NVIDIA has kept with the underlying logic and architecture but enhanced the core in a few ways, like increasing the number of stream processors, improved texture performance, a 512-bit memory interface, and power management enhancements to cope with the demands of modern 3D graphics. On the other hand, the new GPUs are DirectX 10 and Open GL 2.1 compliant and unlike rival ATI, the company will not be formally moving to DirectX 10.1 compliancy just yet, as NVIDIA believes the new features in 10.1 are minor and incremental while some are already implemented in hardware. With only one game, Assassin's Creed that used to support DirectX 10.1, (a recent subsequent patch removed it, generating some controversy), and it's hard to see much progress in this area. Especially when you consider that DirectX 11 slated for next year isn't that far away, so it's quite logical for some developers to jump an incremental version and support the next iteration when it's ripe.
Echoing NVIDIA's recent theme of advancing the usage of GPUs beyond its traditional domains in 3D applications like games, these new GPUs have another side that gaming enthusiasts usually neglect, which happens to be general computing (GPGPU) and like the GeForce 8 and 9 series, these GPUs will support NVIDIA's CUDA technology, with each stream processor executing an instruction thread like a massively parallel computer. Before we proceed to the architectural details, here's a table listing the specifications of the two models available at this moment, the GeForce GTX 280 and 260 next to existing high-end GPUs.
|Model||NVIDIA GeForce GTX 280 1GB||NVIDA GeForce GTX 260 896MB||NVIDIA GeForce 9800 GX2 1GB||NVIDIA GeForce 9800 GTX 512MB||ATI Radeon HD 3870 X2 1GB|
|Core Code||GT200||GT200||G92 x 2||G92||R680 (RV670 x 2)|
|Transistor Count||1400 million||1400 million||1508 million||754 million||1332 million|
|Stream Processors||240 Stream Processors||192 Stream Processors||256 Stream Processors||128 Stream Processors||128 Shader units (640 stream processing units)|
|Stream Processor Clock||1296MHz||1242MHz||1500MHz||1688MHz||825MHz|
|Texture Mapping Units (TMU) or Texture Filtering (TF) units||80||64||128||64||32|
|Raster Operator units (ROP)||32||28||48||24||32|
|Memory Clock||2214MHz GDDR3||1998MHz GDDR3||2000MHz GDDR3||2200MHz GDDR3||1800MHz GDDR3|
|DDR Memory Bus||512-bit||448-bit||256-bit||256-bit||256-bit|
|Ring Bus Memory Controller||NIL||NIL||NIL||NIL||512-bit|
|PCI Express Interface||PCIe ver 2.0 x16||PCIe ver 2.0 x16||PCIe ver 2.0 x16||PCIe ver 2.0 x16||PCIe ver 2.0 x16|
|Molex Power Connectors||Yes (6-pin, 8-pin)||Yes (2 x 6-pin)||Yes (6-pin, 8-pin)||Yes (2 x 6-pin)||Yes (6-pin, 8-pin)|
|Multi GPU Technology||Yes (SLI)||Yes (SLI)||Yes (SLI)||Yes (SLI)||Yes (CrossFireX)|
|DVI Output Support||2 x Dual-Link||2 x Dual-Link||2 x Dual-Link||2 x Dual-Link||2 x Dual-Link|
|HDCP Output Support||Yes||Yes||Yes||Yes||Yes|
|Street Price||US$649||US$399||~US$449 - 529||~US$299||~US$319 - 365|