GeForce 8800 GTS (G80) 640MB vs GeForce 8800 Ultra

Intro

Compare those specs to the GeForce 8800 Ultra, which has clock speeds of 612 MHz on the GPU, and 1080 MHz on the 768 MB of GDDR3 RAM. It features 128 SPUs as well as 64 TAUs and 24 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8800 GTS (G80) 640MB		143 Watts
GeForce 8800 Ultra		171 Watts
	Difference: 28 Watts (20%)

Memory Bandwidth

The GeForce 8800 Ultra should theoretically be quite a bit faster than the GeForce 8800 GTS (G80) 640MB overall. (explain)

GeForce 8800 Ultra		103680 MB/sec
GeForce 8800 GTS (G80) 640MB		63360 MB/sec
	Difference: 40320 (64%)

Texel Rate

The GeForce 8800 Ultra will be much (more or less 59%) more effective at texture filtering than the GeForce 8800 GTS (G80) 640MB. (explain)

GeForce 8800 Ultra		39168 Mtexels/sec
GeForce 8800 GTS (G80) 640MB		24624 Mtexels/sec
	Difference: 14544 (59%)

Pixel Rate

The GeForce 8800 Ultra should be quite a bit (more or less 43%) better at full screen anti-aliasing than the GeForce 8800 GTS (G80) 640MB, and also will be capable of handling higher resolutions while still performing well. (explain)

GeForce 8800 Ultra		14688 Mpixels/sec
GeForce 8800 GTS (G80) 640MB		10260 Mpixels/sec
	Difference: 4428 (43%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of information (counted in megabytes per second) that can be transferred across the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This figure is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.