Radeon HD 3850 1GB vs Radeon HD 4850 1GB

Intro

The Radeon HD 3850 1GB has a core clock speed of 668 MHz and a GDDR3 memory frequency of 828 MHz. It also features a 256-bit memory bus, and uses a 55 nm design. It is made up of 320(64x5) SPUs, 16 TAUs, and 16 Raster Operation Units.

Compare that to the Radeon HD 4850 1GB, which features GPU core speed of 625 MHz, and 1024 MB of GDDR4 memory running at 993 MHz through a 256-bit bus. It also is comprised of 800(160x5) Stream Processors, 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 3850 1GB Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Radeon HD 4850 1GB Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	Radeon HD 3850 1GB	Radeon HD 4850 1GB
Manufacturer	ATi	ATi
Year	Nov 19, 2007	Jun 25, 2008
Code Name	RV670 PRO	RV770 PRO
Fab Process	55 nm	55 nm
Bus	PCIe 2.0 x16/AGP 8x	PCIe 2.0 x16
Memory	1024 MB	1024 MB
Core Speed	668 MHz	625 MHz
Shader Speed	N/A MHz	(N/A) MHz
Memory Speed	828 MHz	993 MHz
Unified Shaders	320(64x5)	800(160x5)
Texture Mapping Units	16	40
Render Output Units	16	16
Bus Type	GDDR3	GDDR4
Bus Width	256-bit	256-bit
DirectX Version	DirectX 10.1	DirectX 10.1
OpenGL Version	OpenGL 3.0	OpenGL 3.0
Power (Max TDP)	75 watts	110 watts
Shader Model	4.1	4.1
Bandwidth	52992 MB/sec	63552 MB/sec
Texel Rate	10688 Mtexels/sec	25000 Mtexels/sec
Pixel Rate	10688 Mpixels/sec	10000 Mpixels/sec

Memory Bandwidth: Bandwidth is the maximum amount of information (measured in MB per second) that can be moved past the external memory interface within a second. It's worked out by multiplying the card's bus width by its memory clock speed. In the case of DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. 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 output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.