Radeon HD 4830 1GB vs Radeon HD 6990

Intro

Compare all of that to the Radeon HD 6990, which comes with GPU core speed of 830 MHz, and 2048 MB of GDDR5 memory set to run at 1250 MHz through a 256-bit bus. It also features 1536 SPUs, 96 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 1GB		95 Watts
Radeon HD 6990		375 Watts
	Difference: 280 Watts (295%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6990 should in theory be much better than the Radeon HD 4830 1GB overall. (explain)

Radeon HD 6990		320000 MB/sec
Radeon HD 4830 1GB		57600 MB/sec
	Difference: 262400 (456%)

Texel Rate

The Radeon HD 6990 should be a lot (more or less 766%) more effective at AF than the Radeon HD 4830 1GB. (explain)

Radeon HD 6990		159360 Mtexels/sec
Radeon HD 4830 1GB		18400 Mtexels/sec
	Difference: 140960 (766%)

Pixel Rate

The Radeon HD 6990 should be quite a bit (about 477%) better at full screen anti-aliasing than the Radeon HD 4830 1GB, and able to handle higher screen resolutions without losing too much performance. (explain)

Radeon HD 6990		53120 Mpixels/sec
Radeon HD 4830 1GB		9200 Mpixels/sec
	Difference: 43920 (477%)

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: Bandwidth is the max amount of data (in units of megabytes per second) that can be moved across the external memory interface in one second. The number is worked out by multiplying the bus width by the speed of its memory. If the card has DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better 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 amount of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The better this number, the better the 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 maximum amount of pixels that the graphics chip can possibly record to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.