The G80 processor debuted with two flavors, the GeForce 8800GTX and the GeForce 8800GTS. The processor core for the GeForce 8800GTX operates at a frequency of 575 MHz and 500 MHz on GeForce 8800GTS. While the rest of the core runs at 575 MHz (or 500 MHz), the shader core has its own independent clock generator. GeForce 8800GTX runs at 1,350 MHz and the 8800GTS' clock speed is 1,200 MHz.
For launch day we received a 320 MB version card from BFG Technologies. In typical BFG fashion, the card was factory overclocked. So for our tests we utilized the card at the level a consumer would expect from BFG. The core on the BFG 8800GTS OC operates at 550 MHz with the shader clock set at 1,300 MHz and the memory running at 800 MHZ (1.6 GHz DDR).
The point of introducing a graphics card that has the same core and less memory is strictly one of product positioning. The GeForce 8800GTS has 12 sets of eight streaming processors in a block for a total 96 SPs. Like ATI's design in R580 and R580+ with its pixel shader units, Nvidia says more units can be added to future designs and some can be taken away. This can be seen in the implementation of 128 streaming processors (16 sets) in the flagship GeForce 8800GTX.
|Graphics Card||Price Band|
|GeForce 8800GTX 768 MB||$599 - $649|
|GeForce 8800GTS 640 MB||$399 - $440|
|GeForce 8800GTS 320 MB||$299 - $329|
So what do you expect when the memory is cut in half? The frame buffer memory is needed to store partially completed frame information. The effect we have seen in the past is that an application cannot begin a test at high image quality settings such as antialiasing while at extremely high resolutions. If the card does not have enough for the task, an error window will show up once the application closes abruptly. Simply put, it means that in some situations the GeForce 8800 GTS 320 MB version could find itself under-equipped for extreme situations.