Radeon HD 4850 X2 512MB vs Radeon HD 5770

Intro

Compare that to the Radeon HD 5770, which comes with clock speeds of 850 MHz on the GPU, and 1200 MHz on the 1024 MB of GDDR5 memory. It features 800(160x5) SPUs along with 40 TAUs and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 5770		108 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 142 Watts (131%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4850 X2 512MB should in theory be quite a bit better than the Radeon HD 5770 overall. (explain)

Radeon HD 4850 X2 512MB		127104 MB/sec
Radeon HD 5770		76800 MB/sec
	Difference: 50304 (66%)

Texel Rate

The Radeon HD 4850 X2 512MB will be much (about 47%) better at texture filtering than the Radeon HD 5770. (explain)

Radeon HD 4850 X2 512MB		50000 Mtexels/sec
Radeon HD 5770		34000 Mtexels/sec
	Difference: 16000 (47%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon HD 4850 X2 512MB is superior to the Radeon HD 5770, and very much so. (explain)

Radeon HD 4850 X2 512MB		20000 Mpixels/sec
Radeon HD 5770		13600 Mpixels/sec
	Difference: 6400 (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: Memory bandwidth is the maximum amount of information (in units of megabytes per second) that can be moved over the external memory interface in one second. It's calculated by multiplying the card's interface width by its memory speed. If it uses DDR memory, it should be multiplied by 2 once 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 anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.