Radeon HD 4850 X2 1GB vs Radeon HD 6770 1GB

Intro

The Radeon HD 4850 X2 1GB comes with a core clock speed of 625 MHz and a GDDR3 memory frequency of 993 MHz. It also makes use of a 256-bit bus, and uses a 55 nm design. It features 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

Compare those specifications to the Radeon HD 6770 1GB, which uses a 40 nm design. ATi has clocked the core speed at 900 MHz. The GDDR5 memory runs at a speed of 1050 MHz on this specific model. It features 800 SPUs along with 40 TAUs and 16 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 4850 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 4850 X2 1GB	Radeon HD 6770 1GB
Manufacturer	ATi	ATi
Year	Nov 7, 2008	January 2011
Code Name	R700	Juniper XT
Fab Process	55 nm	40 nm
Bus	PCIe 2.0 x16 (PCIe bridge)	PCIe x16
Memory	1024 MB (x2)	1024 MB
Core Speed	625 MHz (x2)	900 MHz
Shader Speed	N/A MHz (x2)	(N/A) MHz
Memory Speed	993 MHz (x2)	1050 MHz
Unified Shaders	800(160x5) (x2)	800
Texture Mapping Units	40 (x2)	40
Render Output Units	16 (x2)	16
Bus Type	GDDR3	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)	250 watts	108 watts
Shader Model	4.1	5.0
Bandwidth	127104 MB/sec	67200 MB/sec
Texel Rate	50000 Mtexels/sec	36000 Mtexels/sec
Pixel Rate	20000 Mpixels/sec	14400 Mpixels/sec

Memory Bandwidth: Bandwidth is the max amount of data (counted in MB per second) that can be transported past the external memory interface in a second. The number is calculated by multiplying the card's bus width by its memory clock speed. If it uses DDR type RAM, the result 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 anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total amount of texture units by the core clock 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 processed per second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units by the the core 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 fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.