GeForce 8800 Ultra vs Radeon HD 4890 2GB

Intro

Compare those specs to the Radeon HD 4890 2GB, which makes use of a 55 nm design. AMD has set the core frequency at 1000 MHz. The GDDR5 RAM works at a speed of 975 MHz on this particular card. It features 800(160x5) SPUs as well as 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8800 Ultra		171 Watts
Radeon HD 4890 2GB		190 Watts
	Difference: 19 Watts (11%)

Memory Bandwidth

Performance-wise, the Radeon HD 4890 2GB should in theory be a little bit better than the GeForce 8800 Ultra in general. (explain)

Radeon HD 4890 2GB		124800 MB/sec
GeForce 8800 Ultra		103680 MB/sec
	Difference: 21120 (20%)

Texel Rate

The Radeon HD 4890 2GB should be a little bit (about 2%) faster with regards to texture filtering than the GeForce 8800 Ultra. (explain)

Radeon HD 4890 2GB		40000 Mtexels/sec
GeForce 8800 Ultra		39168 Mtexels/sec
	Difference: 832 (2%)

Pixel Rate

The Radeon HD 4890 2GB is just a bit (more or less 9%) more effective at full screen anti-aliasing than the GeForce 8800 Ultra, and will be capable of handling higher screen resolutions more effectively. (explain)

Radeon HD 4890 2GB		16000 Mpixels/sec
GeForce 8800 Ultra		14688 Mpixels/sec
	Difference: 1312 (9%)

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 (measured in MB per second) that can be transported over the external memory interface within a second. It is calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the 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 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 speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.