Radeon HD 4870 X2 vs Radeon HD 7950

Intro

The Radeon HD 4870 X2 comes with a clock speed of 750 MHz and a GDDR5 memory speed of 900 MHz. It also makes use of a 256-bit bus, and uses a 55 nm design. It is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Compare those specifications to the Radeon HD 7950, which uses a 28 nm design. ATi has set the core speed at 800 MHz. The GDDR5 RAM runs at a speed of 1250 MHz on this specific model. It features 1792 SPUs along with 112 Texture Address Units and 32 Rasterization Operator Units.

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 4870 X2 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Radeon HD 7950 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	Radeon HD 4870 X2	Radeon HD 7950
Manufacturer	ATi	ATi
Year	Aug 12, 2008	January 2012
Code Name	R700	Tahiti Pro
Fab Process	55 nm	28 nm
Bus	PCIe 2.0 x16 (PCIe bridge)	PCIe 3.0 x16
Memory	1024 MB (x2)	1536 MB
Core Speed	750 MHz (x2)	800 MHz
Shader Speed	N/A MHz (x2)	(N/A) MHz
Memory Speed	900 MHz (x2)	1250 MHz
Unified Shaders	800(160x5) (x2)	1792
Texture Mapping Units	40 (x2)	112
Render Output Units	16 (x2)	32
Bus Type	GDDR5	GDDR5
Bus Width	256-bit (x2)	384-bit
DirectX Version	DirectX 10.1	DirectX 11.1
OpenGL Version	OpenGL 3.0	OpenGL 4.2
Power (Max TDP)	350 watts	200 watts
Shader Model	4.1	5.0
Bandwidth	230400 MB/sec	240000 MB/sec
Texel Rate	60000 Mtexels/sec	89600 Mtexels/sec
Pixel Rate	24000 Mpixels/sec	25600 Mpixels/sec

Memory Bandwidth: Bandwidth is the max amount of information (measured in MB per second) that can be moved over the external memory interface in a second. The number is calculated by multiplying the interface width by its memory speed. If it uses DDR type RAM, it must be multiplied by 2 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 higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This number is calculated 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 per second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.