Radeon HD 4850 X2 1GB vs Radeon HD 5770

Intro

Compare all of that to the Radeon HD 5770, which features core clock speeds of 850 MHz on the GPU, and 1200 MHz on the 1024 MB of GDDR5 memory. It features 800(160x5) SPUs as well as 40 TAUs and 16 Rasterization Operator Units.

(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 1GB		250 Watts
	Difference: 142 Watts (131%)

Memory Bandwidth

In theory, the Radeon HD 4850 X2 1GB will be 66% quicker than the Radeon HD 5770 overall, due to its higher data rate. (explain)

Radeon HD 4850 X2 1GB		127104 MB/sec
Radeon HD 5770		76800 MB/sec
	Difference: 50304 (66%)

Texel Rate

The Radeon HD 4850 X2 1GB will be quite a bit (more or less 47%) more effective at anisotropic filtering than the Radeon HD 5770. (explain)

Radeon HD 4850 X2 1GB		50000 Mtexels/sec
Radeon HD 5770		34000 Mtexels/sec
	Difference: 16000 (47%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 4850 X2 1GB is superior to the Radeon HD 5770, and very much so. (explain)

Radeon HD 4850 X2 1GB		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 largest amount of data (counted in megabytes per second) that can be moved across the external memory interface in one second. It is worked out by multiplying the card's bus width by its memory speed. If it uses DDR memory, the result should be multiplied by 2 once again. If 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 high resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the clock speed of the card. 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 also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.