Radeon HD 4850 1GB vs Radeon HD 6870

Intro

Compare that to the Radeon HD 6870, which uses a 40 nm design. AMD has clocked the core speed at 900 MHz. The GDDR5 RAM runs at a frequency of 1050 MHz on this particular card. It features 1120 SPUs along with 56 TAUs and 32 Rasterization Operator 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

Theoretically speaking, the Radeon HD 6870 should perform quite a bit faster than the Radeon HD 4850 1GB in general. (explain)

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

Texel Rate

The Radeon HD 6870 is quite a bit (about 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 a high screen resolution is important to you, then the Radeon HD 6870 is a better choice, 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: Bandwidth is the maximum amount of information (measured in MB per second) that can be transported across the external memory interface in a second. It is calculated by multiplying the card's bus width by the speed of its memory. In the case of DDR memory, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, 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 can be processed in one second. This figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.