Radeon HD 5870 vs Radeon HD 7850

Intro

Compare all that to the Radeon HD 7850, which uses a 28 nm design. AMD has set the core frequency at 860 MHz. The GDDR5 memory works at a speed of 1200 MHz on this specific card. It features 1024 SPUs along with 64 Texture Address Units and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7850		130 Watts
Radeon HD 5870		188 Watts
	Difference: 58 Watts (45%)

Memory Bandwidth

Both cards have exactly the same bandwidth, so theoretically they should perform the same. (explain)

Texel Rate

The Radeon HD 5870 will be a lot (more or less 24%) faster with regards to AF than the Radeon HD 7850. (explain)

Radeon HD 5870		68000 Mtexels/sec
Radeon HD 7850		55040 Mtexels/sec
	Difference: 12960 (24%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon HD 7850 is the winner, not by a very large margin though. (explain)

Radeon HD 7850		27520 Mpixels/sec
Radeon HD 5870		27200 Mpixels/sec
	Difference: 320 (1%)

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 megabytes per second) that can be moved over the external memory interface in a second. It's worked out by multiplying the interface width by its memory clock speed. If it uses DDR memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly record to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.