GeForce 8800 Ultra vs Radeon HD 4790

Intro

Compare that to the Radeon HD 4790, which has a clock speed of 600 MHz and a GDDR5 memory speed of 800 MHz. It also features a 256-bit bus, and makes use of a 55 nm design. It features 640(128x5) SPUs, 32 Texture Address Units, and 16 Raster Operation Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Memory Bandwidth

The GeForce 8800 Ultra should theoretically perform a small bit faster than the Radeon HD 4790 in general. (explain)

GeForce 8800 Ultra		103680 MB/sec
Radeon HD 4790		102400 MB/sec
	Difference: 1280 (1%)

Texel Rate

The GeForce 8800 Ultra is a lot (approximately 104%) faster with regards to anisotropic filtering than the Radeon HD 4790. (explain)

GeForce 8800 Ultra		39168 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 19968 (104%)

Pixel Rate

The GeForce 8800 Ultra should be much (approximately 53%) better at FSAA than the Radeon HD 4790, and should be able to handle higher screen resolutions better. (explain)

GeForce 8800 Ultra		14688 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 5088 (53%)

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 data (measured in MB per second) that can be moved across the external memory interface in one second. The number is worked out by multiplying the bus width by the speed of its memory. In the case of DDR memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.