Radeon HD 3850 X2 vs Radeon HD 4850 512MB

Intro

Compare that to the Radeon HD 4850 512MB, which comes with a GPU core clock speed of 625 MHz, and 512 MB of GDDR3 RAM set to run at 993 MHz through a 256-bit bus. It also is comprised of 800(160x5) Stream Processors, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

The Radeon HD 3850 X2, in theory, should be quite a bit faster than the Radeon HD 4850 512MB overall. (explain)

Radeon HD 3850 X2		105984 MB/sec
Radeon HD 4850 512MB		63552 MB/sec
	Difference: 42432 (67%)

Texel Rate

The Radeon HD 4850 512MB will be a small bit (approximately 17%) faster with regards to anisotropic filtering than the Radeon HD 3850 X2. (explain)

Radeon HD 4850 512MB		25000 Mtexels/sec
Radeon HD 3850 X2		21376 Mtexels/sec
	Difference: 3624 (17%)

Pixel Rate

The Radeon HD 3850 X2 will be a lot (approximately 114%) more effective at anti-aliasing than the Radeon HD 4850 512MB, and will be capable of handling higher screen resolutions without slowing down too much. (explain)

Radeon HD 3850 X2		21376 Mpixels/sec
Radeon HD 4850 512MB		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: Memory bandwidth is the max amount of information (in units of MB per second) that can be moved across the external memory interface in a second. The number is worked out by multiplying the bus width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on many 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.