Radeon HD 4850 X2 512MB vs Radeon R9 285

Intro

Compare all that to the Radeon R9 285, which has a clock speed of 918 MHz and a GDDR5 memory frequency of 1375 MHz. It also makes use of a 256-bit memory bus, and uses a 28 nm design. It features 1792 SPUs, 112 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 285		190 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 60 Watts (32%)

Memory Bandwidth

The Radeon R9 285 should theoretically be quite a bit faster than the Radeon HD 4850 X2 512MB overall. (explain)

Radeon R9 285		176000 MB/sec
Radeon HD 4850 X2 512MB		127104 MB/sec
	Difference: 48896 (38%)

Texel Rate

The Radeon R9 285 will be a lot (more or less 106%) more effective at AF than the Radeon HD 4850 X2 512MB. (explain)

Radeon R9 285		102816 Mtexels/sec
Radeon HD 4850 X2 512MB		50000 Mtexels/sec
	Difference: 52816 (106%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon R9 285 is superior to the Radeon HD 4850 X2 512MB, and very much so. (explain)

Radeon R9 285		29376 Mpixels/sec
Radeon HD 4850 X2 512MB		20000 Mpixels/sec
	Difference: 9376 (47%)

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 maximum amount of information (counted in MB per second) that can be transported past the external memory interface within a second. It is worked out by multiplying the interface width by its memory clock speed. In the case of DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one 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 maximum number of pixels that the graphics chip can possibly write to its 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 many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.