GeForce 8800

DefinitionEngineering sample of the G80


The GeForce 8800 (or G80) series is nVidia's next generation video card/GPU that will fully support Microsoft's upcoming Direct X 10 (DX10) API and Shader Model 4.0 (SM4.0). Though not completely confirmed, it looks as if the 8800 series will come in 2 initial flavors; the 8800 GTS and the 8800 GTX, the later being the most powerful and most expensive.

Models


The GTX version's GPU will be factory clocked at 575Mhz and the board will contain 768MB of GDDR3 memory clocked at 900Mhz (1.8Ghz DDR/effective). The memory will work on a 384bit interface, up from 256bits on the GeForce 7900 GTX. Overall theoretical memory bandwidth is 86GB/s. It will also carry 128 unified vertex and pixel shaders clocked at 1350Mhz.

The GTS version's GPU will be factory clocked at 500Mhz, sport 640MB of GDDR3 memory also clocked at 900Mhz (1.8Ghz DDR/effective). However, the memory interface will be reduced to 320bits with an overall theoretical bandwidth of 64GB/s. The GTS will have a reduced number of unified shaders, 96.

Major differences between previous generations


Perhaps the biggest difference between the G80 (or GeForce 8800) and previous versions is that the GPU has what's called unified shader units. In previous versions of the GeForce series (GeForce 3 series and up) pixel and vertex shaders were seperate units. nVidia decided to combine the units for better performance and operational efficiency. Taking this step has been hailed as both a major risk and a major step forward by industry analysts. However, most seem to agree that unified shader units are the future of GPU's. ATI's upcoming DX10 capable GPU, the R600, will also have unified shader units. Cooling: rumors have said the GTX will use a hybrid water cooling system. The above photo clearly shows an in and out valve for what appears to be water cooling lines. If the final card does indeed sport a water cooling system, it would be a historical event. No video card has ever required a water cooling design to run at stock speeds.

The other differences relate to Microsoft's DX10 API. DX10 was originally scheduled for release at the same time as Windows Vista. However Vista has been delayed until January 2007, and thus DX10 still remains a "beta" product. Among other things, DX10 supports Shader Model 4.0 (SM4.0). DX10 will effectively "raise the bar" for 3D video games with all its new features. Several games, including Crysis, are designed around DX10. Though games like Crysis will support DX9, to get the real eye candy one will need Windows Vista and a DX10 compliant video card. At the moment, only nVidia's G80/GeForce 8800 and ATI's R600 will be DX10 compliant. Thus, the G80 is probably the biggest upgrade in GPU's since the GeForce 3 series.

Release date


Though not confirmed, substantial rumors place the release date of the G80 around the 2nd week of November 2006. Availability is said to be immediate once officially announced by nVidia.

Pricing


As of this date, pricing as not been confirmed by nVidia. However one can expect the GTX version to retail for at least $599 USD, if not more. The GTS version is rumored to be priced around $449-499 USD.

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