Radeon HD 4850 512MB vs Radeon HD 6990

Intro

Compare those specs to the Radeon HD 6990, which features core clock speeds of 830 MHz on the GPU, and 1250 MHz on the 2048 MB of GDDR5 memory. It features 1536 SPUs along with 96 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4850 512MB		110 Watts
Radeon HD 6990		375 Watts
	Difference: 265 Watts (241%)

Memory Bandwidth

In theory, the Radeon HD 6990 is 404% faster than the Radeon HD 4850 512MB overall, due to its greater data rate. (explain)

Radeon HD 6990		320000 MB/sec
Radeon HD 4850 512MB		63552 MB/sec
	Difference: 256448 (404%)

Texel Rate

The Radeon HD 6990 should be much (more or less 537%) more effective at texture filtering than the Radeon HD 4850 512MB. (explain)

Radeon HD 6990		159360 Mtexels/sec
Radeon HD 4850 512MB		25000 Mtexels/sec
	Difference: 134360 (537%)

Pixel Rate

The Radeon HD 6990 will be much (more or less 431%) better at anti-aliasing than the Radeon HD 4850 512MB, and also will be able to handle higher screen resolutions more effectively. (explain)

Radeon HD 6990		53120 Mpixels/sec
Radeon HD 4850 512MB		10000 Mpixels/sec
	Difference: 43120 (431%)

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 information (counted in megabytes per second) that can be transported over the external memory interface in a second. It's calculated by multiplying the bus width by the speed of its memory. In the case of DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This is calculated by multiplying the total number of texture units by the core speed of the chip. The higher this number, 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 most pixels the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.