Radeon HD 7870 vs Radeon RX 6800

Intro

Compare that to the Radeon RX 6800, which comes with a core clock frequency of 1700 MHz and a GDDR6 memory frequency of 2000 MHz. It also makes use of a 256-bit bus, and makes use of a 7 nm design. It is comprised of 3840 SPUs, 240 Texture Address Units, and 96 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7870		175 Watts
Radeon RX 6800		250 Watts
	Difference: 75 Watts (43%)

Memory Bandwidth

The Radeon RX 6800 should theoretically be a lot faster than the Radeon HD 7870 in general. (explain)

Radeon RX 6800		524288 MB/sec
Radeon HD 7870		153600 MB/sec
	Difference: 370688 (241%)

Texel Rate

The Radeon RX 6800 is quite a bit (approximately 410%) faster with regards to anisotropic filtering than the Radeon HD 7870. (explain)

Radeon RX 6800		408000 Mtexels/sec
Radeon HD 7870		80000 Mtexels/sec
	Difference: 328000 (410%)

Pixel Rate

The Radeon RX 6800 will be much (more or less 410%) more effective at AA than the Radeon HD 7870, and also will be capable of handling higher resolutions without slowing down too much. (explain)

Radeon RX 6800		163200 Mpixels/sec
Radeon HD 7870		32000 Mpixels/sec
	Difference: 131200 (410%)

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.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the maximum amount of data (measured in megabytes per second) that can be transferred over the external memory interface in one second. The number is calculated by multiplying the interface width by the speed of its memory. In the case of DDR RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, 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 amount of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total texture units by the core clock speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.