Radeon HD 3850 X2 vs Radeon HD 4870 X2

Intro

Compare those specs to the Radeon HD 4870 X2, which comes with GPU core speed of 750 MHz, and 1024 MB of GDDR5 RAM running at 900 MHz through a 256-bit bus. It also features 800(160x5) Stream Processors, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

As far as performance goes, the Radeon HD 4870 X2 should theoretically be quite a bit superior to the Radeon HD 3850 X2 overall. (explain)

Radeon HD 4870 X2		230400 MB/sec
Radeon HD 3850 X2		105984 MB/sec
	Difference: 124416 (117%)

Texel Rate

The Radeon HD 4870 X2 will be much (approximately 181%) better at texture filtering than the Radeon HD 3850 X2. (explain)

Radeon HD 4870 X2		60000 Mtexels/sec
Radeon HD 3850 X2		21376 Mtexels/sec
	Difference: 38624 (181%)

Pixel Rate

The Radeon HD 4870 X2 is a small bit (more or less 12%) faster with regards to full screen anti-aliasing than the Radeon HD 3850 X2, and should be capable of handling higher resolutions better. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
Radeon HD 3850 X2		21376 Mpixels/sec
	Difference: 2624 (12%)

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 maximum 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 its memory clock speed. In the case of DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.