GeForce 8800 Ultra vs Radeon HD 4890 1GB

Intro

Compare all that to the Radeon HD 4890 1GB, which features a core clock frequency of 1000 MHz and a GDDR5 memory frequency of 975 MHz. It also makes use of a 256-bit memory bus, and uses a 55 nm design. It is made up of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8800 Ultra		171 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 19 Watts (11%)

Memory Bandwidth

Theoretically, the Radeon HD 4890 1GB should perform a small bit faster than the GeForce 8800 Ultra in general. (explain)

Radeon HD 4890 1GB		124800 MB/sec
GeForce 8800 Ultra		103680 MB/sec
	Difference: 21120 (20%)

Texel Rate

The Radeon HD 4890 1GB should be just a bit (about 2%) more effective at texture filtering than the GeForce 8800 Ultra. (explain)

Radeon HD 4890 1GB		40000 Mtexels/sec
GeForce 8800 Ultra		39168 Mtexels/sec
	Difference: 832 (2%)

Pixel Rate

The Radeon HD 4890 1GB will be just a bit (more or less 9%) faster with regards to full screen anti-aliasing than the GeForce 8800 Ultra, and will be capable of handling higher screen resolutions without losing too much performance. (explain)

Radeon HD 4890 1GB		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 largest amount of information (measured in megabytes per second) that can be transferred over the external memory interface in one second. The number is worked out by multiplying the card's interface width by its memory speed. If the card has DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high 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 amount of texture units of the card by the core clock speed of the chip. The higher 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 that the graphics chip can possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.