Radeon HD 4870 X2 vs Radeon HD 6770

Intro

Compare those specifications to the Radeon HD 6770, which uses a 40 nm design. AMD has clocked the core speed at 900 MHz. The GDDR5 memory runs at a speed of 1050 MHz on this particular model. It features 800 SPUs along with 40 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 6770		108 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 242 Watts (224%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4870 X2 should in theory be much superior to the Radeon HD 6770 overall. (explain)

Radeon HD 4870 X2		230400 MB/sec
Radeon HD 6770		67200 MB/sec
	Difference: 163200 (243%)

Texel Rate

The Radeon HD 4870 X2 should be much (more or less 67%) more effective at anisotropic filtering than the Radeon HD 6770. (explain)

Radeon HD 4870 X2		60000 Mtexels/sec
Radeon HD 6770		36000 Mtexels/sec
	Difference: 24000 (67%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon HD 4870 X2 is superior to the Radeon HD 6770, by far. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
Radeon HD 6770		14400 Mpixels/sec
	Difference: 9600 (67%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of data (counted in MB per second) that can be transferred over the external memory interface in a second. The number is calculated by multiplying the bus width by the speed of its memory. If the card has DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the graphics card will be at 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 the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.