Radeon HD 3850 1GB vs Radeon HD 4850 2GB

Intro

Compare all that to the Radeon HD 4850 2GB, which comes with core clock speeds of 625 MHz on the GPU, and 993 MHz on the 2048 MB of GDDR4 RAM. It features 800(160x5) SPUs as well as 40 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 1GB		75 Watts
Radeon HD 4850 2GB		110 Watts
	Difference: 35 Watts (47%)

Memory Bandwidth

The Radeon HD 4850 2GB, in theory, should be a small bit faster than the Radeon HD 3850 1GB overall. (explain)

Radeon HD 4850 2GB		63552 MB/sec
Radeon HD 3850 1GB		52992 MB/sec
	Difference: 10560 (20%)

Texel Rate

The Radeon HD 4850 2GB should be much (approximately 134%) more effective at texture filtering than the Radeon HD 3850 1GB. (explain)

Radeon HD 4850 2GB		25000 Mtexels/sec
Radeon HD 3850 1GB		10688 Mtexels/sec
	Difference: 14312 (134%)

Pixel Rate

The Radeon HD 3850 1GB should be a bit (approximately 7%) better at FSAA than the Radeon HD 4850 2GB, and should be able to handle higher screen resolutions without losing too much performance. (explain)

Radeon HD 3850 1GB		10688 Mpixels/sec
Radeon HD 4850 2GB		10000 Mpixels/sec
	Difference: 688 (7%)

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: Memory bandwidth is the max amount of information (counted in MB per second) that can be transferred over the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory clock speed. If it uses DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of 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 calculated by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.