Radeon HD 4850 X2 1GB vs Radeon HD 6770

Intro

The Radeon HD 4850 X2 1GB comes with a GPU core clock speed of 625 MHz, and the 1024 MB of GDDR3 RAM runs at 993 MHz through a 256-bit bus. It also is comprised of 800(160x5) Stream Processors, 40 Texture Address Units, and 16 ROPs.

Compare those specs to the Radeon HD 6770, which has core speeds of 900 MHz on the GPU, and 1050 MHz on the 512 MB of GDDR5 RAM. It features 800 SPUs along with 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 4850 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 4850 X2 1GB	Radeon HD 6770
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)	512 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: Memory bandwidth is the maximum amount of information (in units of megabytes per second) that can be transported across the external memory interface within a second. It's calculated by multiplying the card's interface width by its memory speed. If it uses DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, 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 texture map elements (texels) that can be 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 card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Raster Operations Pipelines 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 many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.