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

Intro

The Radeon HD 4850 1GB has a core clock speed of 625 MHz and a GDDR4 memory frequency of 993 MHz. It also uses a 256-bit bus, and makes use of a 55 nm design. It features 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.

Compare all that to the Radeon HD 4850 X2 1GB, which uses a 55 nm design. ATi has set the core frequency at 625 MHz. The GDDR3 memory runs at a frequency of 993 MHz on this card. It features 800(160x5) SPUs as well as 40 Texture Address Units 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 4850 X2 1GB Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	Radeon HD 4850 1GB	Radeon HD 4850 X2 1GB
Manufacturer	ATi	ATi
Year	Jun 25, 2008	Nov 7, 2008
Code Name	RV770 PRO	R700
Fab Process	55 nm	55 nm
Bus	PCIe 2.0 x16	PCIe 2.0 x16 (PCIe bridge)
Memory	1024 MB	1024 MB (x2)
Core Speed	625 MHz	625 MHz (x2)
Shader Speed	N/A MHz	(N/A) MHz (x2)
Memory Speed	993 MHz	993 MHz (x2)
Unified Shaders	800(160x5)	800(160x5) (x2)
Texture Mapping Units	40	40 (x2)
Render Output Units	16	16 (x2)
Bus Type	GDDR4	GDDR3
Bus Width	256-bit	256-bit (x2)
DirectX Version	DirectX 10.1	DirectX 10.1
OpenGL Version	OpenGL 3.0	OpenGL 3.0
Power (Max TDP)	110 watts	250 watts
Shader Model	4.1	4.1
Bandwidth	63552 MB/sec	127104 MB/sec
Texel Rate	25000 Mtexels/sec	50000 Mtexels/sec
Pixel Rate	10000 Mpixels/sec	20000 Mpixels/sec

Memory Bandwidth: Memory bandwidth is the largest amount of data (counted in megabytes per second) that can be moved past the external memory interface within a second. The number is worked out by multiplying the bus width by its memory clock speed. If it uses DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.