Radeon HD 7870 vs Radeon HD 7950

Intro

The Radeon HD 7870 comes with a clock frequency of 1000 MHz and a GDDR5 memory speed of 1200 MHz. It also makes use of a 256-bit memory bus, and uses a 28 nm design. It is made up of 1280 SPUs, 80 TAUs, and 32 ROPs.

Compare those specifications to the Radeon HD 7950, which comes with core speeds of 800 MHz on the GPU, and 1250 MHz on the 1536 MB of GDDR5 memory. It features 1792 SPUs as well as 112 Texture Address Units and 32 ROPs.

Price Comparison

Radeon HD 7870 Amazon.com

Radeon HD 7950 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
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	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: Memory bandwidth is the max amount of information (counted in megabytes per second) that can be transferred across the external memory interface in a second. The number is worked out by multiplying the card's bus width by its memory clock speed. If the card has DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The better the texel rate, the better the graphics 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 amount of pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.