Radeon HD 4830 512MB vs Radeon HD 7990

Intro

Compare that to the Radeon HD 7990, which makes use of a 28 nm design. AMD has set the core frequency at 950 MHz. The GDDR5 RAM works at a frequency of 1500 MHz on this particular card. It features 2048 SPUs as well as 128 TAUs and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 512MB		95 Watts
Radeon HD 7990		375 Watts
	Difference: 280 Watts (295%)

Memory Bandwidth

Performance-wise, the Radeon HD 7990 should in theory be quite a bit superior to the Radeon HD 4830 512MB in general. (explain)

Radeon HD 7990		576000 MB/sec
Radeon HD 4830 512MB		57600 MB/sec
	Difference: 518400 (900%)

Texel Rate

The Radeon HD 7990 will be a lot (more or less 1222%) more effective at texture filtering than the Radeon HD 4830 512MB. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 224800 (1222%)

Pixel Rate

The Radeon HD 7990 will be much (more or less 561%) more effective at full screen anti-aliasing than the Radeon HD 4830 512MB, and should be capable of handling higher screen resolutions without losing too much performance. (explain)

Radeon HD 7990		60800 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 51600 (561%)

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 largest amount of data (in units of megabytes per second) that can be transferred past the external memory interface within a second. It is calculated by multiplying the card's bus width by the speed of its memory. 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 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 texture map elements (texels) that are processed per second. This is worked out by multiplying the total number of texture units by the core speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.