Radeon HD 3850 256MB vs Radeon HD 4830 1GB

Intro

Compare those specifications to the Radeon HD 4830 1GB, which has core speeds of 575 MHz on the GPU, and 900 MHz on the 1024 MB of GDDR4 memory. It features 640(128x5) SPUs as well as 32 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3850 256MB		75 Watts
Radeon HD 4830 1GB		95 Watts
	Difference: 20 Watts (27%)

Memory Bandwidth

The Radeon HD 4830 1GB, in theory, should be a bit faster than the Radeon HD 3850 256MB in general. (explain)

Radeon HD 4830 1GB		57600 MB/sec
Radeon HD 3850 256MB		52992 MB/sec
	Difference: 4608 (9%)

Texel Rate

The Radeon HD 4830 1GB will be a lot (about 72%) better at AF than the Radeon HD 3850 256MB. (explain)

Radeon HD 4830 1GB		18400 Mtexels/sec
Radeon HD 3850 256MB		10688 Mtexels/sec
	Difference: 7712 (72%)

Pixel Rate

The Radeon HD 3850 256MB should be a little bit (about 16%) more effective at full screen anti-aliasing than the Radeon HD 4830 1GB, and capable of handling higher screen resolutions more effectively. (explain)

Radeon HD 3850 256MB		10688 Mpixels/sec
Radeon HD 4830 1GB		9200 Mpixels/sec
	Difference: 1488 (16%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of information (measured in megabytes per second) that can be transported past the external memory interface within a second. It's calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly record to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.