Radeon HD 4850 X2 512MB vs Radeon HD 6770 1GB

Intro

The Radeon HD 4850 X2 512MB comes with a clock frequency of 625 MHz and a GDDR3 memory speed of 993 MHz. It also features a 256-bit memory bus, and uses a 55 nm design. It is made up of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.

Compare all of that to the Radeon HD 6770 1GB, which comes with core clock speeds of 900 MHz on the GPU, and 1050 MHz on the 1024 MB of GDDR5 memory. It features 800 SPUs as well as 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 512MB 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 512MB	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	512 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: Memory 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 interface width by its memory speed. In the case of DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster 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 are processed per second. This figure is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.