Radeon HD 6990 vs Radeon RX 6600 XT

Intro

Compare all that to the Radeon RX 6600 XT, which has a core clock frequency of 1968 MHz and a GDDR6 memory speed of 2000 MHz. It also uses a 128-bit memory bus, and uses a 7 nm design. It is made up of 2048 SPUs, 128 TAUs, and 64 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon RX 6600 XT		160 Watts
Radeon HD 6990		375 Watts
	Difference: 215 Watts (134%)

Memory Bandwidth

Performance-wise, the Radeon HD 6990 should in theory be much superior to the Radeon RX 6600 XT overall. (explain)

Radeon HD 6990		320000 MB/sec
Radeon RX 6600 XT		262144 MB/sec
	Difference: 57856 (22%)

Texel Rate

The Radeon RX 6600 XT is much (more or less 58%) more effective at anisotropic filtering than the Radeon HD 6990. (explain)

Radeon RX 6600 XT		251904 Mtexels/sec
Radeon HD 6990		159360 Mtexels/sec
	Difference: 92544 (58%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon RX 6600 XT is a better choice, and very much so. (explain)

Radeon RX 6600 XT		125952 Mpixels/sec
Radeon HD 6990		53120 Mpixels/sec
	Difference: 72832 (137%)

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 moved across the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory clock speed. In the case of DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher 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 number of texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total texture units by the core clock speed of the chip. The better this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.