Radeon HD 4850 2GB vs Radeon HD 7950

Intro

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

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4850 2GB		110 Watts
Radeon HD 7950		200 Watts
	Difference: 90 Watts (82%)

Memory Bandwidth

Performance-wise, the Radeon HD 7950 should theoretically be much better than the Radeon HD 4850 2GB overall. (explain)

Radeon HD 7950		240000 MB/sec
Radeon HD 4850 2GB		63552 MB/sec
	Difference: 176448 (278%)

Texel Rate

The Radeon HD 7950 will be quite a bit (approximately 258%) faster with regards to texture filtering than the Radeon HD 4850 2GB. (explain)

Radeon HD 7950		89600 Mtexels/sec
Radeon HD 4850 2GB		25000 Mtexels/sec
	Difference: 64600 (258%)

Pixel Rate

The Radeon HD 7950 should be a lot (more or less 156%) more effective at anti-aliasing than the Radeon HD 4850 2GB, and also should be capable of handling higher screen resolutions better. (explain)

Radeon HD 7950		25600 Mpixels/sec
Radeon HD 4850 2GB		10000 Mpixels/sec
	Difference: 15600 (156%)

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 max amount of data (measured in MB per second) that can be transferred across the external memory interface in one second. The number is calculated by multiplying the card's interface width by the speed of its memory. If it uses DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This is worked out by multiplying the total texture units of the card 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 in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.