Radeon HD 4850 X2 1GB vs Radeon HD 7870

Intro

Compare that to the Radeon HD 7870, which makes use of a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 memory runs at a frequency of 1200 MHz on this specific card. It features 1280 SPUs as well as 80 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7870		175 Watts
Radeon HD 4850 X2 1GB		250 Watts
	Difference: 75 Watts (43%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7870 should be quite a bit faster than the Radeon HD 4850 X2 1GB in general. (explain)

Radeon HD 7870		153600 MB/sec
Radeon HD 4850 X2 1GB		127104 MB/sec
	Difference: 26496 (21%)

Texel Rate

The Radeon HD 7870 will be much (about 60%) better at anisotropic filtering than the Radeon HD 4850 X2 1GB. (explain)

Radeon HD 7870		80000 Mtexels/sec
Radeon HD 4850 X2 1GB		50000 Mtexels/sec
	Difference: 30000 (60%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 7870 is superior to the Radeon HD 4850 X2 1GB, by far. (explain)

Radeon HD 7870		32000 Mpixels/sec
Radeon HD 4850 X2 1GB		20000 Mpixels/sec
	Difference: 12000 (60%)

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 (measured in MB per second) that can be moved across the external memory interface in one second. The number is calculated by multiplying the card's bus width by its memory speed. In the case of DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher 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 amount of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total number of texture units by the core speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

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