Radeon HD 4890 2GB vs Radeon HD 6970

Intro

Compare that to the Radeon HD 6970, which features a core clock frequency of 880 MHz and a GDDR5 memory frequency of 1375 MHz. It also makes use of a 256-bit bus, and uses a 40 nm design. It is comprised of 1536 SPUs, 96 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4890 2GB		190 Watts
Radeon HD 6970		250 Watts
	Difference: 60 Watts (32%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6970 should theoretically be quite a bit superior to the Radeon HD 4890 2GB in general. (explain)

Radeon HD 6970		176000 MB/sec
Radeon HD 4890 2GB		124800 MB/sec
	Difference: 51200 (41%)

Texel Rate

The Radeon HD 6970 should be quite a bit (approximately 111%) faster with regards to anisotropic filtering than the Radeon HD 4890 2GB. (explain)

Radeon HD 6970		84480 Mtexels/sec
Radeon HD 4890 2GB		40000 Mtexels/sec
	Difference: 44480 (111%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon HD 6970 is superior to the Radeon HD 4890 2GB, and very much so. (explain)

Radeon HD 6970		28160 Mpixels/sec
Radeon HD 4890 2GB		16000 Mpixels/sec
	Difference: 12160 (76%)

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 maximum amount of information (in units of MB per second) that can be moved across the external memory interface within a second. It is worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better 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 amount of texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total number 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 in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on lots of 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.