Radeon HD 4850 512MB vs Radeon HD 6950 2GB

Intro

Compare all of that to the Radeon HD 6950 2GB, which features a core clock speed of 800 MHz and a GDDR5 memory speed of 1250 MHz. It also uses a 256-bit bus, and makes use of a 40 nm design. It is comprised of 1408 SPUs, 88 TAUs, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4850 512MB		110 Watts
Radeon HD 6950 2GB		200 Watts
	Difference: 90 Watts (82%)

Memory Bandwidth

In theory, the Radeon HD 6950 2GB should be 152% quicker than the Radeon HD 4850 512MB overall, due to its higher data rate. (explain)

Radeon HD 6950 2GB		160000 MB/sec
Radeon HD 4850 512MB		63552 MB/sec
	Difference: 96448 (152%)

Texel Rate

The Radeon HD 6950 2GB is quite a bit (about 182%) better at texture filtering than the Radeon HD 4850 512MB. (explain)

Radeon HD 6950 2GB		70400 Mtexels/sec
Radeon HD 4850 512MB		25000 Mtexels/sec
	Difference: 45400 (182%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 6950 2GB is the winner, by far. (explain)

Radeon HD 6950 2GB		25600 Mpixels/sec
Radeon HD 4850 512MB		10000 Mpixels/sec
	Difference: 15600 (156%)

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 maximum amount of data (counted in MB per second) that can be transferred over the external memory interface in a second. It is calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the 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 amount of texture map elements (texels) that are processed in one second. This is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly record to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many 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.