Radeon HD 4870 2GB vs Radeon HD 5850

Intro

The Radeon HD 4870 2GB comes with clock speeds of 750 MHz on the GPU, and 900 MHz on the 2048 MB of GDDR5 RAM. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Compare all that to the Radeon HD 5850, which uses a 40 nm design. ATi has clocked the core frequency at 725 MHz. The GDDR5 RAM runs at a speed of 1000 MHz on this model. It features 1440(288x5) SPUs as well as 72 Texture Address Units and 32 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 4870 2GB Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Radeon HD 5850 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	Radeon HD 4870 2GB	Radeon HD 5850
Manufacturer	ATi	ATi
Year	Jun 25, 2008	September 30, 2009
Code Name	RV770 XT	Cypress PRO
Fab Process	55 nm	40 nm
Bus	PCIe 2.0 x16	PCIe 2.1 x16
Memory	2048 MB	1024 MB
Core Speed	750 MHz	725 MHz
Shader Speed	N/A MHz	(N/A) MHz
Memory Speed	900 MHz	1000 MHz
Unified Shaders	800(160x5)	1440(288x5)
Texture Mapping Units	40	72
Render Output Units	16	32
Bus Type	GDDR5	GDDR5
Bus Width	256-bit	256-bit
DirectX Version	DirectX 10.1	DirectX 11
OpenGL Version	OpenGL 3.0	OpenGL 3.2
Power (Max TDP)	150 watts	151 watts
Shader Model	4.1	5.0
Bandwidth	115200 MB/sec	128000 MB/sec
Texel Rate	30000 Mtexels/sec	52200 Mtexels/sec
Pixel Rate	12000 Mpixels/sec	23200 Mpixels/sec

Memory Bandwidth: Memory bandwidth is the max amount of information (in units of megabytes per second) that can be transferred across the external memory interface in a second. It is calculated by multiplying the bus width by its memory speed. If it uses DDR memory, it should be multiplied by 2 once 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 AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of 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 better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few 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.