Radeon HD 3870 X2 1GB vs Radeon HD 6770 1GB

Intro

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

Compare all of that to the Radeon HD 6770 1GB, which comes with GPU clock speed of 900 MHz, and 1024 MB of GDDR5 RAM set to run at 1050 MHz through a 128-bit bus. It also is made up of 800 SPUs, 40 TAUs, 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 1GB Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	Radeon HD 3870 X2 1GB	Radeon HD 6770 1GB
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)	1024 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 maximum amount of data (in units of megabytes per second) that can be transferred over the external memory interface in one second. The number is worked out by multiplying the interface width by its memory speed. If it uses DDR memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

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