Radeon HD 7870 vs Radeon HD 7950 3GB

Intro

The Radeon HD 7870 comes with a clock frequency of 1000 MHz and a GDDR5 memory speed of 1200 MHz. It also uses a 256-bit bus, and uses a 28 nm design. It features 1280 SPUs, 80 Texture Address Units, and 32 Raster Operation Units.

Compare that to the Radeon HD 7950 3GB, which uses a 28 nm design. AMD has set the core speed at 800 MHz. The GDDR5 RAM runs at a frequency of 1250 MHz on this specific model. It features 1792 SPUs along with 112 Texture Address Units and 32 ROPs.

Price Comparison

Radeon HD 7870 Amazon.com

Radeon HD 7950 3GB 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 7870	Radeon HD 7950 3GB
Manufacturer	AMD	AMD
Year	March 2012	January 2012
Code Name	Pitcairn XT	Tahiti Pro
Fab Process	28 nm	28 nm
Bus	PCIe 3.0 x16	PCIe 3.0 x16
Memory	2048 MB	3072 MB
Core Speed	1000 MHz	800 MHz
Shader Speed	N/A MHz	(N/A) MHz
Memory Speed	1200 MHz (4800 MHz effective)	1250 MHz (5000 MHz effective)
Unified Shaders	1280	1792
Texture Mapping Units	80	112
Render Output Units	32	32
Bus Type	GDDR5	GDDR5
Bus Width	256-bit	384-bit
DirectX Version	DirectX 11.1	DirectX 11.1
OpenGL Version	OpenGL 4.2	OpenGL 4.2
Power (Max TDP)	175 watts	200 watts
Shader Model	5.0	5.0
Bandwidth	153600 MB/sec	240000 MB/sec
Texel Rate	80000 Mtexels/sec	89600 Mtexels/sec
Pixel Rate	32000 Mpixels/sec	25600 Mpixels/sec

Memory Bandwidth: Memory bandwidth is the maximum amount of data (in units of MB per second) that can be moved past the external memory interface within a second. It is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the faster 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 per second. This number is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.