Radeon HD 6990 vs Radeon RX 6600 XT

Intro

Compare that to the Radeon RX 6600 XT, which comes with a core clock frequency of 1968 MHz and a GDDR6 memory frequency of 2000 MHz. It also makes use of a 128-bit memory bus, and uses a 7 nm design. It features 2048 SPUs, 128 Texture Address Units, 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

In theory, the Radeon HD 6990 should be a lot faster than 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 will be a lot (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 running with a high screen resolution is important to you, then the Radeon RX 6600 XT is a better choice, by far. (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: Memory bandwidth is the largest amount of information (measured in megabytes per second) that can be moved past the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. If the card has DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster 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 amount of texture map elements (texels) that are applied in one second. This is calculated by multiplying the total texture units by the core speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly record to its 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 core clock speed. 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 lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.