Radeon HD 4850 X2 1GB vs Radeon HD 6770 1GB

Intro

Compare that to the Radeon HD 6770 1GB, which features a clock speed of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also features a 128-bit memory bus, and makes use of a 40 nm design. It features 800 SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6770 1GB		108 Watts
Radeon HD 4850 X2 1GB		250 Watts
	Difference: 142 Watts (131%)

Memory Bandwidth

The Radeon HD 4850 X2 1GB, in theory, should perform quite a bit faster than the Radeon HD 6770 1GB overall. (explain)

Radeon HD 4850 X2 1GB		127104 MB/sec
Radeon HD 6770 1GB		67200 MB/sec
	Difference: 59904 (89%)

Texel Rate

The Radeon HD 4850 X2 1GB should be quite a bit (about 39%) better at anisotropic filtering than the Radeon HD 6770 1GB. (explain)

Radeon HD 4850 X2 1GB		50000 Mtexels/sec
Radeon HD 6770 1GB		36000 Mtexels/sec
	Difference: 14000 (39%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 4850 X2 1GB is a better choice, by far. (explain)

Radeon HD 4850 X2 1GB		20000 Mpixels/sec
Radeon HD 6770 1GB		14400 Mpixels/sec
	Difference: 5600 (39%)

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: Memory bandwidth is the largest amount of information (measured in megabytes per second) that can be moved over the external memory interface within a second. The number is calculated by multiplying the interface width by the speed of its memory. If the card has DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, 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 number of texture map elements (texels) that are processed per second. This number is calculated by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.