Radeon HD 4850 1GB vs Radeon HD 6870

Intro

Compare all that to the Radeon HD 6870, which features a GPU core clock speed of 900 MHz, and 1024 MB of GDDR5 RAM running at 1050 MHz through a 256-bit bus. It also is made up of 1120 Stream Processors, 56 Texture Address Units, 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 6870		151 Watts
	Difference: 41 Watts (37%)

Memory Bandwidth

The Radeon HD 6870 should in theory perform a lot faster than the Radeon HD 4850 1GB overall. (explain)

Radeon HD 6870		134400 MB/sec
Radeon HD 4850 1GB		63552 MB/sec
	Difference: 70848 (111%)

Texel Rate

The Radeon HD 6870 should be a lot (more or less 102%) more effective at anisotropic filtering than the Radeon HD 4850 1GB. (explain)

Radeon HD 6870		50400 Mtexels/sec
Radeon HD 4850 1GB		25000 Mtexels/sec
	Difference: 25400 (102%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 6870 is the winner, by far. (explain)

Radeon HD 6870		28800 Mpixels/sec
Radeon HD 4850 1GB		10000 Mpixels/sec
	Difference: 18800 (188%)

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 largest amount of information (counted in MB per second) that can be transferred across the external memory interface within a second. It's worked out by multiplying the interface width by the speed of its memory. If the card has DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This number is worked out by multiplying the total texture units by the core clock speed of the chip. The higher this number, the better the graphics 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 most pixels that the graphics chip can possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.