Radeon HD 5870 vs Radeon HD 6850

Intro

Compare all of that to the Radeon HD 6850, which uses a 40 nm design. AMD has clocked the core frequency at 775 MHz. The GDDR5 memory is set to run at a speed of 1000 MHz on this specific card. It features 960 SPUs along with 48 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6850		127 Watts
Radeon HD 5870		188 Watts
	Difference: 61 Watts (48%)

Memory Bandwidth

In theory, the Radeon HD 5870 will be 20% quicker than the Radeon HD 6850 in general, due to its higher bandwidth. (explain)

Radeon HD 5870		153600 MB/sec
Radeon HD 6850		128000 MB/sec
	Difference: 25600 (20%)

Texel Rate

The Radeon HD 5870 is much (about 83%) faster with regards to texture filtering than the Radeon HD 6850. (explain)

Radeon HD 5870		68000 Mtexels/sec
Radeon HD 6850		37200 Mtexels/sec
	Difference: 30800 (83%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon HD 5870 is superior to the Radeon HD 6850, not by a very large margin though. (explain)

Radeon HD 5870		27200 Mpixels/sec
Radeon HD 6850		24800 Mpixels/sec
	Difference: 2400 (10%)

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 maximum amount of data (counted in MB per second) that can be transported across the external memory interface within a second. It's calculated by multiplying the interface width by its memory speed. In the case of DDR memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.