Radeon HD 4870 1GB vs Radeon HD 5850

Intro

Compare all that to the Radeon HD 5850, which comes with GPU core speed of 725 MHz, and 1024 MB of GDDR5 RAM set to run at 1000 MHz through a 256-bit bus. It also is made up of 1440(288x5) SPUs, 72 TAUs, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 1GB		150 Watts
Radeon HD 5850		151 Watts
	Difference: 1 Watts (1%)

Memory Bandwidth

The Radeon HD 5850, in theory, should perform a bit faster than the Radeon HD 4870 1GB in general. (explain)

Radeon HD 5850		128000 MB/sec
Radeon HD 4870 1GB		115200 MB/sec
	Difference: 12800 (11%)

Texel Rate

The Radeon HD 5850 should be a lot (about 74%) more effective at AF than the Radeon HD 4870 1GB. (explain)

Radeon HD 5850		52200 Mtexels/sec
Radeon HD 4870 1GB		30000 Mtexels/sec
	Difference: 22200 (74%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon HD 5850 is a better choice, by far. (explain)

Radeon HD 5850		23200 Mpixels/sec
Radeon HD 4870 1GB		12000 Mpixels/sec
	Difference: 11200 (93%)

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 (counted in MB per second) that can be transported past the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics 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 most pixels that the graphics chip could possibly write to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs 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 is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.