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

Intro

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

Compare that to the Radeon HD 4850 X2 512MB, which comes with core speeds of 625 MHz on the GPU, and 993 MHz on the 512 MB of GDDR3 memory. 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 512MB Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	Radeon HD 4850 1GB	Radeon HD 4850 X2 512MB
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	512 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 max amount of data (measured in MB per second) that can be transported past the external memory interface in one second. The number is calculated by multiplying the bus width by its memory speed. If the card has DDR RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This is calculated by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the video 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 graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.