Radeon HD 3870 X2 1GB vs Radeon HD 6950 2GB

Intro

The Radeon HD 3870 X2 1GB features a clock speed of 825 MHz and a GDDR4 memory speed of 1126 MHz. It also makes use of a 256-bit memory bus, and uses a 55 nm design. It is made up of 320(64x5) SPUs, 16 Texture Address Units, and 16 ROPs.

Compare all of that to the Radeon HD 6950 2GB, which comes with clock speeds of 800 MHz on the GPU, and 1250 MHz on the 2048 MB of GDDR5 RAM. It features 1408 SPUs as well as 88 Texture Address Units 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 3870 X2 1GB Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Radeon HD 6950 2GB Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	Radeon HD 3870 X2 1GB	Radeon HD 6950 2GB
Manufacturer	ATi	ATi
Year	Jan 28, 2008	December 2010
Code Name	R680	Cayman Pro
Fab Process	55 nm	40 nm
Bus	PCIe 2.0 x16/(internal PCIe 1.1 x16)	PCIe x16
Memory	1024 MB (x2)	2048 MB
Core Speed	825 MHz (x2)	800 MHz
Shader Speed	N/A MHz (x2)	(N/A) MHz
Memory Speed	1126 MHz (x2)	1250 MHz
Unified Shaders	320(64x5) (x2)	1408
Texture Mapping Units	16 (x2)	88
Render Output Units	16 (x2)	32
Bus Type	GDDR4	GDDR5
Bus Width	256-bit (x2)	256-bit
DirectX Version	DirectX 10.1	DirectX 11
OpenGL Version	OpenGL 3.0	OpenGL 4.1
Power (Max TDP)	N/A watts	200 watts
Shader Model	4.1	5.0
Bandwidth	144128 MB/sec	160000 MB/sec
Texel Rate	26400 Mtexels/sec	70400 Mtexels/sec
Pixel Rate	26400 Mpixels/sec	25600 Mpixels/sec

Memory Bandwidth: Memory bandwidth is the maximum amount of data (in units of MB per second) that can be transported past the external memory interface within a second. It's worked out by multiplying the bus width by its memory clock speed. If it uses DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the better 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 amount of texture map elements (texels) that are processed per second. This is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to the 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 card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as 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, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.