Radeon HD 4850 X2 1GB vs Radeon HD 7950 3GB

Intro

Compare those specifications to the Radeon HD 7950 3GB, which features clock speeds of 800 MHz on the GPU, and 1250 MHz on the 3072 MB of GDDR5 memory. It features 1792 SPUs as well as 112 Texture Address Units and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7950 3GB		200 Watts
Radeon HD 4850 X2 1GB		250 Watts
	Difference: 50 Watts (25%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7950 3GB should be quite a bit faster than the Radeon HD 4850 X2 1GB overall. (explain)

Radeon HD 7950 3GB		240000 MB/sec
Radeon HD 4850 X2 1GB		127104 MB/sec
	Difference: 112896 (89%)

Texel Rate

The Radeon HD 7950 3GB should be a lot (more or less 79%) better at AF than the Radeon HD 4850 X2 1GB. (explain)

Radeon HD 7950 3GB		89600 Mtexels/sec
Radeon HD 4850 X2 1GB		50000 Mtexels/sec
	Difference: 39600 (79%)

Pixel Rate

The Radeon HD 7950 3GB is quite a bit (approximately 28%) faster with regards to AA than the Radeon HD 4850 X2 1GB, and also should be capable of handling higher resolutions better. (explain)

Radeon HD 7950 3GB		25600 Mpixels/sec
Radeon HD 4850 X2 1GB		20000 Mpixels/sec
	Difference: 5600 (28%)

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 data (in units of megabytes per second) that can be transported over the external memory interface in a second. It is worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka 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 ability to get to the max fill rate.