GeForce 8800 Ultra vs Radeon HD 4850 X2 1GB

Intro

Compare those specs to the Radeon HD 4850 X2 1GB, which has GPU clock speed of 625 MHz, and 1024 MB of GDDR3 RAM running at 993 MHz through a 256-bit bus. It also features 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8800 Ultra		171 Watts
Radeon HD 4850 X2 1GB		250 Watts
	Difference: 79 Watts (46%)

Memory Bandwidth

Theoretically, the Radeon HD 4850 X2 1GB should perform much faster than the GeForce 8800 Ultra overall. (explain)

Radeon HD 4850 X2 1GB		127104 MB/sec
GeForce 8800 Ultra		103680 MB/sec
	Difference: 23424 (23%)

Texel Rate

The Radeon HD 4850 X2 1GB should be quite a bit (approximately 28%) faster with regards to texture filtering than the GeForce 8800 Ultra. (explain)

Radeon HD 4850 X2 1GB		50000 Mtexels/sec
GeForce 8800 Ultra		39168 Mtexels/sec
	Difference: 10832 (28%)

Pixel Rate

The Radeon HD 4850 X2 1GB will be much (more or less 36%) faster with regards to anti-aliasing than the GeForce 8800 Ultra, and will be able to handle higher resolutions without slowing down too much. (explain)

Radeon HD 4850 X2 1GB		20000 Mpixels/sec
GeForce 8800 Ultra		14688 Mpixels/sec
	Difference: 5312 (36%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the largest amount of data (counted in megabytes per second) that can be moved over the external memory interface in a second. The number is calculated by multiplying the card's bus width by its memory clock speed. If it uses DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This figure is worked out by multiplying the total texture units by the core clock speed of the chip. The better this number, the better the video 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 most pixels that 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 Raster Operations Pipelines by the the core clock speed. 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 output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.