Radeon HD 3850 X2 vs Radeon HD 4850 2GB

Intro

Compare all of that to the Radeon HD 4850 2GB, which comes with clock speeds of 625 MHz on the GPU, and 993 MHz on the 2048 MB of GDDR4 RAM. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

In theory, the Radeon HD 3850 X2 will be 67% quicker than the Radeon HD 4850 2GB overall, due to its greater bandwidth. (explain)

Radeon HD 3850 X2		105984 MB/sec
Radeon HD 4850 2GB		63552 MB/sec
	Difference: 42432 (67%)

Texel Rate

The Radeon HD 4850 2GB is a little bit (about 17%) faster with regards to texture filtering than the Radeon HD 3850 X2. (explain)

Radeon HD 4850 2GB		25000 Mtexels/sec
Radeon HD 3850 X2		21376 Mtexels/sec
	Difference: 3624 (17%)

Pixel Rate

The Radeon HD 3850 X2 will be a lot (more or less 114%) better at AA than the Radeon HD 4850 2GB, and also will be capable of handling higher resolutions while still performing well. (explain)

Radeon HD 3850 X2		21376 Mpixels/sec
Radeon HD 4850 2GB		10000 Mpixels/sec
	Difference: 11376 (114%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of information (measured in megabytes per second) that can be transported over the external memory interface within a second. It's worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the 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 number of pixels that the graphics chip can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of colour ROPs by the the core speed of the card. 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 lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.