GeForce 8800 GTS (G80) 640MB vs GeForce GTS 450

Intro

Compare those specs to the GeForce GTS 450, which has core clock speeds of 783 MHz on the GPU, and 902 MHz on the 512 MB of GDDR5 RAM. It features 192 SPUs along with 32 TAUs and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTS 450		106 Watts
GeForce 8800 GTS (G80) 640MB		143 Watts
	Difference: 37 Watts (35%)

Memory Bandwidth

The GeForce 8800 GTS (G80) 640MB should in theory be a little bit faster than the GeForce GTS 450 overall. (explain)

GeForce 8800 GTS (G80) 640MB		63360 MB/sec
GeForce GTS 450		57728 MB/sec
	Difference: 5632 (10%)

Texel Rate

The GeForce GTS 450 should be a small bit (approximately 2%) more effective at AF than the GeForce 8800 GTS (G80) 640MB. (explain)

GeForce GTS 450		25056 Mtexels/sec
GeForce 8800 GTS (G80) 640MB		24624 Mtexels/sec
	Difference: 432 (2%)

Pixel Rate

The GeForce GTS 450 is much (about 22%) better at AA than the GeForce 8800 GTS (G80) 640MB, and should be able to handle higher resolutions better. (explain)

GeForce GTS 450		12528 Mpixels/sec
GeForce 8800 GTS (G80) 640MB		10260 Mpixels/sec
	Difference: 2268 (22%)

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: Bandwidth is the largest amount of information (counted in MB per second) that can be transported over the external memory interface in one second. It's worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.