Radeon HD 4770 vs Radeon HD 6950

Intro

Compare that to the Radeon HD 6950, which features a GPU core clock speed of 800 MHz, and 1024 MB of GDDR5 memory running at 1250 MHz through a 256-bit bus. It also is comprised of 1408 Stream Processors, 88 TAUs, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4770		80 Watts
Radeon HD 6950		200 Watts
	Difference: 120 Watts (150%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6950 should be a lot faster than the Radeon HD 4770 overall. (explain)

Radeon HD 6950		160000 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 108800 (213%)

Texel Rate

The Radeon HD 6950 is much (about 193%) faster with regards to texture filtering than the Radeon HD 4770. (explain)

Radeon HD 6950		70400 Mtexels/sec
Radeon HD 4770		24000 Mtexels/sec
	Difference: 46400 (193%)

Pixel Rate

The Radeon HD 6950 should be quite a bit (more or less 113%) better at full screen anti-aliasing than the Radeon HD 4770, and able to handle higher screen resolutions without slowing down too much. (explain)

Radeon HD 6950		25600 Mpixels/sec
Radeon HD 4770		12000 Mpixels/sec
	Difference: 13600 (113%)

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 transferred over the external memory interface in one second. It's calculated by multiplying the interface width by the speed of its memory. If it uses DDR type RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better 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 amount of texture map elements (texels) that can be applied in one second. This is worked out by multiplying the total number of texture units 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 in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to its local memory per second - measured in millions of pixels per second. The figure 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 drawing the pixels (image) on the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.