Radeon HD 7870 vs Radeon HD 7950 3GB

Intro

The Radeon HD 7870 features a GPU core clock speed of 1000 MHz, and the 2048 MB of GDDR5 RAM is set to run at 1200 MHz through a 256-bit bus. It also features 1280 Stream Processors, 80 TAUs, and 32 Raster Operation Units.

Compare those specifications to the Radeon HD 7950 3GB, which features core clock speeds of 800 MHz on the GPU, and 1250 MHz on the 3072 MB of GDDR5 RAM. It features 1792 SPUs along with 112 TAUs and 32 Rasterization Operator Units.

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 (counted in MB per second) that can be moved past the external memory interface in a second. It's worked out by multiplying the card's interface width by its memory speed. In the case of DDR memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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