Radeon HD 4890 2GB vs Radeon HD 6750

Intro

Compare all that to the Radeon HD 6750, which features clock speeds of 725 MHz on the GPU, and 1000 MHz on the 512 MB of GDDR5 RAM. It features 720 SPUs as well as 36 TAUs and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6750		86 Watts
Radeon HD 4890 2GB		190 Watts
	Difference: 104 Watts (121%)

Memory Bandwidth

Performance-wise, the Radeon HD 4890 2GB should in theory be a lot superior to the Radeon HD 6750 in general. (explain)

Radeon HD 4890 2GB		124800 MB/sec
Radeon HD 6750		64000 MB/sec
	Difference: 60800 (95%)

Texel Rate

The Radeon HD 4890 2GB will be much (about 53%) faster with regards to texture filtering than the Radeon HD 6750. (explain)

Radeon HD 4890 2GB		40000 Mtexels/sec
Radeon HD 6750		26100 Mtexels/sec
	Difference: 13900 (53%)

Pixel Rate

The Radeon HD 4890 2GB will be much (more or less 38%) better at full screen anti-aliasing than the Radeon HD 6750, and will be capable of handling higher resolutions without slowing down too much. (explain)

Radeon HD 4890 2GB		16000 Mpixels/sec
Radeon HD 6750		11600 Mpixels/sec
	Difference: 4400 (38%)

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 moved over the external memory interface in one second. The number is worked out by multiplying the interface width by its memory speed. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. 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 processed in one second. This figure is calculated by multiplying the total number of texture units of the card 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 applied in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.