Radeon HD 4550 256MB vs Radeon HD 7990

Intro

Compare those specs to the Radeon HD 7990, which uses a 28 nm design. AMD has set the core frequency at 950 MHz. The GDDR5 memory runs at a speed of 1500 MHz on this specific model. It features 2048 SPUs along with 128 TAUs and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4550 256MB		25 Watts
Radeon HD 7990		375 Watts
	Difference: 350 Watts (1400%)

Memory Bandwidth

Theoretically, the Radeon HD 7990 should be a lot faster than the Radeon HD 4550 256MB in general. (explain)

Radeon HD 7990		576000 MB/sec
Radeon HD 4550 256MB		12800 MB/sec
	Difference: 563200 (4400%)

Texel Rate

The Radeon HD 7990 is a lot (approximately 4967%) better at texture filtering than the Radeon HD 4550 256MB. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon HD 4550 256MB		4800 Mtexels/sec
	Difference: 238400 (4967%)

Pixel Rate

If running with lots of anti-aliasing 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 4550 256MB		2400 Mpixels/sec
	Difference: 58400 (2433%)

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 (counted in MB per second) that can be moved past the external memory interface in a second. It's worked out by multiplying the card's bus width by its memory speed. If the card has DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher this number, the better the 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 maximum amount of pixels that the graphics card could possibly write to its local memory in one 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 of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.