Radeon HD 7870 vs Radeon HD 7950

Intro

The Radeon HD 7870 comes with clock speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 memory. It features 1280 SPUs as well as 80 Texture Address Units and 32 Rasterization Operator Units.

Compare that to the Radeon HD 7950, which uses a 28 nm design. ATi has set the core frequency at 800 MHz. The GDDR5 memory is set to run at a frequency of 1250 MHz on this particular model. It features 1792 SPUs as well as 112 TAUs and 32 ROPs.

Price Comparison

Please note that the price comparisons are based on search keywords, and might not be the exact same card listed on this page. We have no control over the accuracy of their search results.

Radeon HD 7870 Amazon.com Other US-based stores

Radeon HD 7950 Amazon.com Other US-based stores

Specifications

Model	Radeon HD 7870	Radeon HD 7950
Manufacturer	ATi	ATi
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	1536 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: Bandwidth is the largest amount of data (in units of MB per second) that can be moved across the external memory interface in a second. It is worked out by multiplying the interface width by its memory speed. If it uses DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.