Radeon HD 4870 1GB vs Radeon HD 7950

Intro

Compare that to the Radeon HD 7950, which features a clock speed of 800 MHz and a GDDR5 memory frequency of 1250 MHz. It also uses a 384-bit bus, and uses a 28 nm design. It is comprised of 1792 SPUs, 112 TAUs, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 1GB		150 Watts
Radeon HD 7950		200 Watts
	Difference: 50 Watts (33%)

Memory Bandwidth

The Radeon HD 7950 should in theory be quite a bit faster than the Radeon HD 4870 1GB in general. (explain)

Radeon HD 7950		240000 MB/sec
Radeon HD 4870 1GB		115200 MB/sec
	Difference: 124800 (108%)

Texel Rate

The Radeon HD 7950 will be a lot (approximately 199%) faster with regards to AF than the Radeon HD 4870 1GB. (explain)

Radeon HD 7950		89600 Mtexels/sec
Radeon HD 4870 1GB		30000 Mtexels/sec
	Difference: 59600 (199%)

Pixel Rate

The Radeon HD 7950 will be much (about 113%) more effective at AA than the Radeon HD 4870 1GB, and also will be capable of handling higher screen resolutions without losing too much performance. (explain)

Radeon HD 7950		25600 Mpixels/sec
Radeon HD 4870 1GB		12000 Mpixels/sec
	Difference: 13600 (113%)

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: Memory bandwidth is the maximum amount of information (counted in megabytes per second) that can be transported over the external memory interface within a second. It is calculated by multiplying the bus width by its memory clock speed. If it uses DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. 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 applied in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

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