Radeon HD 4850 1GB vs Radeon HD 7970

Intro

Compare those specs to the Radeon HD 7970, which comes with a GPU core clock speed of 925 MHz, and 3072 MB of GDDR5 RAM running at 1375 MHz through a 384-bit bus. It also is comprised of 2048 Stream Processors, 128 TAUs, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4850 1GB		110 Watts
Radeon HD 7970		250 Watts
	Difference: 140 Watts (127%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7970 is 315% faster than the Radeon HD 4850 1GB overall, because of its higher data rate. (explain)

Radeon HD 7970		264000 MB/sec
Radeon HD 4850 1GB		63552 MB/sec
	Difference: 200448 (315%)

Texel Rate

The Radeon HD 7970 will be much (more or less 374%) better at AF than the Radeon HD 4850 1GB. (explain)

Radeon HD 7970		118400 Mtexels/sec
Radeon HD 4850 1GB		25000 Mtexels/sec
	Difference: 93400 (374%)

Pixel Rate

The Radeon HD 7970 is much (about 196%) better at full screen anti-aliasing than the Radeon HD 4850 1GB, and should be able to handle higher screen resolutions more effectively. (explain)

Radeon HD 7970		29600 Mpixels/sec
Radeon HD 4850 1GB		10000 Mpixels/sec
	Difference: 19600 (196%)

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.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the maximum amount of information (in units of megabytes per second) that can be transported past the external memory interface in a second. It's worked out by multiplying the bus width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, 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 worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.