Radeon HD 3850 512MB vs Radeon HD 7990

Intro

Compare those specs to the Radeon HD 7990, which comes with clock speeds of 950 MHz on the GPU, and 1500 MHz on the 3072 MB of GDDR5 memory. It features 2048 SPUs along with 128 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3850 512MB		75 Watts
Radeon HD 7990		375 Watts
	Difference: 300 Watts (400%)

Memory Bandwidth

As far as performance goes, the Radeon HD 7990 should in theory be a lot better than the Radeon HD 3850 512MB overall. (explain)

Radeon HD 7990		576000 MB/sec
Radeon HD 3850 512MB		52992 MB/sec
	Difference: 523008 (987%)

Texel Rate

The Radeon HD 7990 should be much (more or less 2175%) more effective at AF than the Radeon HD 3850 512MB. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon HD 3850 512MB		10688 Mtexels/sec
	Difference: 232512 (2175%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 7990 is the winner, by far. (explain)

Radeon HD 7990		60800 Mpixels/sec
Radeon HD 3850 512MB		10688 Mpixels/sec
	Difference: 50112 (469%)

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 transported over the external memory interface in a second. It is worked out by multiplying the bus width by its memory clock speed. If the card has DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.