Radeon HD 4830 512MB vs Radeon HD 7990

Intro

Compare those specs to the Radeon HD 7990, which features a clock frequency of 950 MHz and a GDDR5 memory speed of 1500 MHz. It also makes use of a 384-bit memory bus, and makes use of a 28 nm design. It is made up of 2048 SPUs, 128 TAUs, and 32 Raster Operation 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 theoretically be a lot better than 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 quite a bit (more or less 1222%) more effective at anisotropic 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

If using a high resolution is important to you, then the Radeon HD 7990 is a better choice, and very much so. (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: Memory bandwidth is the maximum amount of information (measured in MB per second) that can be transferred past the external memory interface within a second. It's calculated by multiplying the bus width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This number 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 video 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 the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.