Radeon HD 4850 X2 512MB vs Radeon HD 7850

Intro

Compare that to the Radeon HD 7850, which features GPU core speed of 860 MHz, and 2048 MB of GDDR5 memory set to run at 1200 MHz through a 256-bit bus. It also is comprised of 1024 SPUs, 64 TAUs, and 32 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7850		130 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 120 Watts (92%)

Memory Bandwidth

The Radeon HD 7850 should theoretically be a lot faster than the Radeon HD 4850 X2 512MB in general. (explain)

Radeon HD 7850		153600 MB/sec
Radeon HD 4850 X2 512MB		127104 MB/sec
	Difference: 26496 (21%)

Texel Rate

The Radeon HD 7850 is a bit (more or less 10%) faster with regards to AF than the Radeon HD 4850 X2 512MB. (explain)

Radeon HD 7850		55040 Mtexels/sec
Radeon HD 4850 X2 512MB		50000 Mtexels/sec
	Difference: 5040 (10%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 7850 is a better choice, by a large margin. (explain)

Radeon HD 7850		27520 Mpixels/sec
Radeon HD 4850 X2 512MB		20000 Mpixels/sec
	Difference: 7520 (38%)

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 transported across the external memory interface in one second. It is calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR memory, the result should be multiplied by 2 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 AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the most pixels the video card can possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many 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.