Radeon HD 4850 X2 1GB vs Radeon R9 390 8G

Intro

Compare that to the Radeon R9 390 8G, which makes use of a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 RAM runs at a speed of 1500 MHz on this specific model. It features 2560 SPUs as well as 160 Texture Address Units and 64 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4850 X2 1GB		250 Watts
Radeon R9 390 8G		275 Watts
	Difference: 25 Watts (10%)

Memory Bandwidth

As far as performance goes, the Radeon R9 390 8G should theoretically be much better than the Radeon HD 4850 X2 1GB overall. (explain)

Radeon R9 390 8G		384000 MB/sec
Radeon HD 4850 X2 1GB		127104 MB/sec
	Difference: 256896 (202%)

Texel Rate

The Radeon R9 390 8G is much (approximately 220%) better at AF than the Radeon HD 4850 X2 1GB. (explain)

Radeon R9 390 8G		160000 Mtexels/sec
Radeon HD 4850 X2 1GB		50000 Mtexels/sec
	Difference: 110000 (220%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon R9 390 8G is the winner, by a large margin. (explain)

Radeon R9 390 8G		64000 Mpixels/sec
Radeon HD 4850 X2 1GB		20000 Mpixels/sec
	Difference: 44000 (220%)

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 max amount of data (in units of megabytes per second) that can be transferred over the external memory interface in a second. It is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 once again. If 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 high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the card's 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 output rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.