Radeon HD 4790 vs Radeon HD 4850 X2 1GB

Intro

Compare all that to the Radeon HD 4850 X2 1GB, which makes use of a 55 nm design. AMD has set the core frequency at 625 MHz. The GDDR3 RAM works at a frequency of 993 MHz on this specific model. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

Performance-wise, the Radeon HD 4850 X2 1GB should in theory be a lot better than the Radeon HD 4790 overall. (explain)

Radeon HD 4850 X2 1GB		127104 MB/sec
Radeon HD 4790		102400 MB/sec
	Difference: 24704 (24%)

Texel Rate

The Radeon HD 4850 X2 1GB will be much (approximately 160%) more effective at texture filtering than the Radeon HD 4790. (explain)

Radeon HD 4850 X2 1GB		50000 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 30800 (160%)

Pixel Rate

The Radeon HD 4850 X2 1GB is quite a bit (approximately 108%) faster with regards to FSAA than the Radeon HD 4790, and able to handle higher screen resolutions better. (explain)

Radeon HD 4850 X2 1GB		20000 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 10400 (108%)

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 past the external memory interface within a second. It is worked out by multiplying the bus width by its memory clock speed. If it uses DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's 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 are applied per second. This is calculated by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core 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 quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.