GeForce 8800 Ultra vs Radeon HD 4870 2GB

Intro

Compare all of that to the Radeon HD 4870 2GB, which makes use of a 55 nm design. ATi has clocked the core frequency at 750 MHz. The GDDR5 RAM is set to run at a frequency of 900 MHz on this card. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 2GB		150 Watts
GeForce 8800 Ultra		171 Watts
	Difference: 21 Watts (14%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4870 2GB should be a little bit faster than the GeForce 8800 Ultra in general. (explain)

Radeon HD 4870 2GB		115200 MB/sec
GeForce 8800 Ultra		103680 MB/sec
	Difference: 11520 (11%)

Texel Rate

The GeForce 8800 Ultra is quite a bit (about 31%) more effective at texture filtering than the Radeon HD 4870 2GB. (explain)

GeForce 8800 Ultra		39168 Mtexels/sec
Radeon HD 4870 2GB		30000 Mtexels/sec
	Difference: 9168 (31%)

Pixel Rate

The GeForce 8800 Ultra should be a lot (more or less 22%) faster with regards to FSAA than the Radeon HD 4870 2GB, and should be able to handle higher resolutions without losing too much performance. (explain)

GeForce 8800 Ultra		14688 Mpixels/sec
Radeon HD 4870 2GB		12000 Mpixels/sec
	Difference: 2688 (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 megabytes per second) that can be transferred over the external memory interface in a second. It is worked out by multiplying the interface width by the speed of its memory. If it uses DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This is worked out by multiplying the total amount of texture units of the card by the core clock 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 one second.

Pixel Rate: Pixel rate is the maximum amount 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 number of Render Output Units 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 rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.