Radeon HD 3850 1GB vs Radeon HD 4850 X2 1GB

Intro

Compare all of that to the Radeon HD 4850 X2 1GB, which features a clock frequency of 625 MHz and a GDDR3 memory frequency of 993 MHz. It also uses a 256-bit bus, and uses a 55 nm design. It is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3850 1GB		75 Watts
Radeon HD 4850 X2 1GB		250 Watts
	Difference: 175 Watts (233%)

Memory Bandwidth

The Radeon HD 4850 X2 1GB should theoretically perform quite a bit faster than the Radeon HD 3850 1GB in general. (explain)

Radeon HD 4850 X2 1GB		127104 MB/sec
Radeon HD 3850 1GB		52992 MB/sec
	Difference: 74112 (140%)

Texel Rate

The Radeon HD 4850 X2 1GB will be a lot (about 368%) better at anisotropic filtering than the Radeon HD 3850 1GB. (explain)

Radeon HD 4850 X2 1GB		50000 Mtexels/sec
Radeon HD 3850 1GB		10688 Mtexels/sec
	Difference: 39312 (368%)

Pixel Rate

The Radeon HD 4850 X2 1GB will be quite a bit (about 87%) better at full screen anti-aliasing than the Radeon HD 3850 1GB, and should be capable of handling higher resolutions more effectively. (explain)

Radeon HD 4850 X2 1GB		20000 Mpixels/sec
Radeon HD 3850 1GB		10688 Mpixels/sec
	Difference: 9312 (87%)

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 data (measured in MB per second) that can be transported across the external memory interface in a second. It's worked out by multiplying the interface width by its memory clock speed. In the case of DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This number 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 graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels the video card can possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.