Radeon HD 3850 X2 vs Radeon HD 4870 512MB

Intro

Compare those specs to the Radeon HD 4870 512MB, which comes with a GPU core clock speed of 750 MHz, and 512 MB of GDDR5 memory set to run at 900 MHz through a 256-bit bus. It also features 800(160x5) Stream Processors, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

As far as performance goes, the Radeon HD 4870 512MB should theoretically be just a bit better than the Radeon HD 3850 X2 overall. (explain)

Radeon HD 4870 512MB		115200 MB/sec
Radeon HD 3850 X2		105984 MB/sec
	Difference: 9216 (9%)

Texel Rate

The Radeon HD 4870 512MB is quite a bit (approximately 40%) better at anisotropic filtering than the Radeon HD 3850 X2. (explain)

Radeon HD 4870 512MB		30000 Mtexels/sec
Radeon HD 3850 X2		21376 Mtexels/sec
	Difference: 8624 (40%)

Pixel Rate

The Radeon HD 3850 X2 is a lot (about 78%) faster with regards to AA than the Radeon HD 4870 512MB, and also will be able to handle higher resolutions without slowing down too much. (explain)

Radeon HD 3850 X2		21376 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 9376 (78%)

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 (counted in megabytes per second) that can be transferred past the external memory interface in a second. It's worked out by multiplying the card's bus width by its memory clock speed. If the card has DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, 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 number of texture map elements (texels) that are applied in one second. This figure is calculated by multiplying the total amount 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 in one second.

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