Radeon HD 4890 1GB vs Radeon HD 6950

Intro

Compare all that to the Radeon HD 6950, which features core clock speeds of 800 MHz on the GPU, and 1250 MHz on the 1024 MB of GDDR5 memory. It features 1408 SPUs along with 88 TAUs and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4890 1GB		190 Watts
Radeon HD 6950		200 Watts
	Difference: 10 Watts (5%)

Memory Bandwidth

Theoretically, the Radeon HD 6950 should be a lot faster than the Radeon HD 4890 1GB in general. (explain)

Radeon HD 6950		160000 MB/sec
Radeon HD 4890 1GB		124800 MB/sec
	Difference: 35200 (28%)

Texel Rate

The Radeon HD 6950 will be a lot (about 76%) better at texture filtering than the Radeon HD 4890 1GB. (explain)

Radeon HD 6950		70400 Mtexels/sec
Radeon HD 4890 1GB		40000 Mtexels/sec
	Difference: 30400 (76%)

Pixel Rate

The Radeon HD 6950 should be much (more or less 60%) faster with regards to AA than the Radeon HD 4890 1GB, and also should be capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 6950		25600 Mpixels/sec
Radeon HD 4890 1GB		16000 Mpixels/sec
	Difference: 9600 (60%)

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 (in units of MB per second) that can be moved past the external memory interface in one second. The number is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one 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 graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.