Radeon HD 4850 2GB vs Radeon HD 6750 1GB

Intro

Compare that to the Radeon HD 6750 1GB, which uses a 40 nm design. AMD has clocked the core frequency at 725 MHz. The GDDR5 memory is set to run at a speed of 1000 MHz on this card. It features 720 SPUs along with 36 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6750 1GB		86 Watts
Radeon HD 4850 2GB		110 Watts
	Difference: 24 Watts (28%)

Memory Bandwidth

The Radeon HD 6750 1GB, in theory, should perform just a bit faster than the Radeon HD 4850 2GB in general. (explain)

Radeon HD 6750 1GB		64000 MB/sec
Radeon HD 4850 2GB		63552 MB/sec
	Difference: 448 (1%)

Texel Rate

The Radeon HD 6750 1GB should be a little bit (approximately 4%) more effective at texture filtering than the Radeon HD 4850 2GB. (explain)

Radeon HD 6750 1GB		26100 Mtexels/sec
Radeon HD 4850 2GB		25000 Mtexels/sec
	Difference: 1100 (4%)

Pixel Rate

The Radeon HD 6750 1GB is a small bit (more or less 16%) more effective at anti-aliasing than the Radeon HD 4850 2GB, and will be capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 6750 1GB		11600 Mpixels/sec
Radeon HD 4850 2GB		10000 Mpixels/sec
	Difference: 1600 (16%)

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 (counted in MB per second) that can be moved over the external memory interface within a second. It is calculated by multiplying the bus width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 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 AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This number is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.