Radeon HD 4850 1GB vs Radeon HD 6770

Intro

The Radeon HD 4850 1GB makes use of a 55 nm design. ATi has set the core speed at 625 MHz. The GDDR4 RAM is set to run at a frequency of 993 MHz on this particular model. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.

Compare all that to the Radeon HD 6770, which uses a 40 nm design. ATi has clocked the core speed at 900 MHz. The GDDR5 RAM is set to run at a speed of 1050 MHz on this specific model. It features 800 SPUs as well as 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 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 1GB	Radeon HD 6770
Manufacturer	ATi	ATi
Year	Jun 25, 2008	January 2011
Code Name	RV770 PRO	Juniper XT
Fab Process	55 nm	40 nm
Bus	PCIe 2.0 x16	PCIe x16
Memory	1024 MB	512 MB
Core Speed	625 MHz	900 MHz
Shader Speed	N/A MHz	(N/A) MHz
Memory Speed	993 MHz	1050 MHz
Unified Shaders	800(160x5)	800
Texture Mapping Units	40	40
Render Output Units	16	16
Bus Type	GDDR4	GDDR5
Bus Width	256-bit	128-bit
DirectX Version	DirectX 10.1	DirectX 11
OpenGL Version	OpenGL 3.0	OpenGL 4.1
Power (Max TDP)	110 watts	108 watts
Shader Model	4.1	5.0
Bandwidth	63552 MB/sec	67200 MB/sec
Texel Rate	25000 Mtexels/sec	36000 Mtexels/sec
Pixel Rate	10000 Mpixels/sec	14400 Mpixels/sec

Memory Bandwidth: Bandwidth is the largest amount of data (counted in megabytes per second) that can be transferred over the external memory interface in a second. It's worked out by multiplying the card's bus width by its memory speed. In the case of DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied 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 video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.