Radeon HD 5870 vs Radeon HD 6870

Intro

The Radeon HD 5870 comes with a clock frequency of 850 MHz and a GDDR5 memory frequency of 1200 MHz. It also features a 256-bit memory bus, and makes use of a 40 nm design. It is made up of 1600(320x5) SPUs, 80 Texture Address Units, and 32 ROPs.

Compare that to the Radeon HD 6870, which has a clock speed of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also makes use of a 256-bit bus, and makes use of a 40 nm design. It features 1120 SPUs, 56 TAUs, and 32 ROPs.

Price Comparison

Radeon HD 5870 Amazon.com

Radeon HD 6870 Amazon.com

Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.

Specifications

Model	Radeon HD 5870	Radeon HD 6870
Manufacturer	AMD	AMD
Year	September 23, 2009	October 2010
Code Name	Cypress XT	Barts XT
Fab Process	40 nm	40 nm
Bus	PCIe 2.1 x16	PCIe x16
Memory	1024 MB	1024 MB
Core Speed	850 MHz	900 MHz
Shader Speed	N/A MHz	(N/A) MHz
Memory Speed	1200 MHz (4800 MHz effective)	1050 MHz (4200 MHz effective)
Unified Shaders	1600(320x5)	1120
Texture Mapping Units	80	56
Render Output Units	32	32
Bus Type	GDDR5	GDDR5
Bus Width	256-bit	256-bit
DirectX Version	DirectX 11	DirectX 11
OpenGL Version	OpenGL 3.2	OpenGL 4.1
Power (Max TDP)	188 watts	151 watts
Shader Model	5.0	5.0
Bandwidth	153600 MB/sec	134400 MB/sec
Texel Rate	68000 Mtexels/sec	50400 Mtexels/sec
Pixel Rate	27200 Mpixels/sec	28800 Mpixels/sec

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 worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and high 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 number of texture units of the card by the core speed of the chip. The higher 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 one second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to its local memory per second - measured in millions of pixels per second. The number 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 filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.