Radeon HD 4830 1GB vs Radeon HD 7990

Intro

Compare all that to the Radeon HD 7990, which has core speeds of 950 MHz on the GPU, and 1500 MHz on the 3072 MB of GDDR5 memory. It features 2048 SPUs as well as 128 TAUs and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 1GB		95 Watts
Radeon HD 7990		375 Watts
	Difference: 280 Watts (295%)

Memory Bandwidth

In theory, the Radeon HD 7990 should be 900% quicker than the Radeon HD 4830 1GB overall, due to its greater bandwidth. (explain)

Radeon HD 7990		576000 MB/sec
Radeon HD 4830 1GB		57600 MB/sec
	Difference: 518400 (900%)

Texel Rate

The Radeon HD 7990 should be much (approximately 1222%) more effective at AF than the Radeon HD 4830 1GB. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon HD 4830 1GB		18400 Mtexels/sec
	Difference: 224800 (1222%)

Pixel Rate

The Radeon HD 7990 should be quite a bit (more or less 561%) better at FSAA than the Radeon HD 4830 1GB, and should be able to handle higher resolutions without slowing down too much. (explain)

Radeon HD 7990		60800 Mpixels/sec
Radeon HD 4830 1GB		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 max amount of information (in units of megabytes per second) that can be transferred over the external memory interface in a second. It is calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better 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 in one second. This number is worked out by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the the core 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 fill rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.