Radeon HD 3870 X2 1GB vs Radeon HD 6770

Intro

The Radeon HD 3870 X2 1GB has a core clock frequency of 825 MHz and a GDDR4 memory frequency of 1126 MHz. It also makes use of a 256-bit bus, and makes use of a 55 nm design. It features 320(64x5) SPUs, 16 Texture Address Units, and 16 Raster Operation Units.

Compare those specifications to the Radeon HD 6770, which comes with a GPU core clock speed of 900 MHz, and 512 MB of GDDR5 memory set to run at 1050 MHz through a 128-bit bus. It also is made up of 800 Stream Processors, 40 Texture Address Units, and 16 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 6770 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	Radeon HD 3870 X2 1GB	Radeon HD 6770
Manufacturer	ATi	ATi
Year	Jan 28, 2008	January 2011
Code Name	R680	Juniper XT
Fab Process	55 nm	40 nm
Bus	PCIe 2.0 x16/(internal PCIe 1.1 x16)	PCIe x16
Memory	1024 MB (x2)	512 MB
Core Speed	825 MHz (x2)	900 MHz
Shader Speed	N/A MHz (x2)	(N/A) MHz
Memory Speed	1126 MHz (x2)	1050 MHz
Unified Shaders	320(64x5) (x2)	800
Texture Mapping Units	16 (x2)	40
Render Output Units	16 (x2)	16
Bus Type	GDDR4	GDDR5
Bus Width	256-bit (x2)	128-bit
DirectX Version	DirectX 10.1	DirectX 11
OpenGL Version	OpenGL 3.0	OpenGL 4.1
Power (Max TDP)	N/A watts	108 watts
Shader Model	4.1	5.0
Bandwidth	144128 MB/sec	67200 MB/sec
Texel Rate	26400 Mtexels/sec	36000 Mtexels/sec
Pixel Rate	26400 Mpixels/sec	14400 Mpixels/sec

Memory Bandwidth: Bandwidth is the max amount of data (measured in megabytes per second) that can be transported past the external memory interface within a second. The number is worked out by multiplying the card's bus 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 card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the video 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 in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output 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 get to the maximum fill rate.