Radeon HD 5870 vs Radeon HD 6790

Intro

Compare that to the Radeon HD 6790, which makes use of a 40 nm design. AMD has clocked the core frequency at 840 MHz. The GDDR5 RAM is set to run at a frequency of 1050 MHz on this model. It features 800 SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6790		150 Watts
Radeon HD 5870		188 Watts
	Difference: 38 Watts (25%)

Memory Bandwidth

The Radeon HD 5870 should theoretically perform a bit faster than the Radeon HD 6790 overall. (explain)

Radeon HD 5870		153600 MB/sec
Radeon HD 6790		134400 MB/sec
	Difference: 19200 (14%)

Texel Rate

The Radeon HD 5870 should be quite a bit (about 102%) better at anisotropic filtering than the Radeon HD 6790. (explain)

Radeon HD 5870		68000 Mtexels/sec
Radeon HD 6790		33600 Mtexels/sec
	Difference: 34400 (102%)

Pixel Rate

The Radeon HD 5870 is quite a bit (approximately 102%) more effective at full screen anti-aliasing than the Radeon HD 6790, and also will be capable of handling higher resolutions while still performing well. (explain)

Radeon HD 5870		27200 Mpixels/sec
Radeon HD 6790		13440 Mpixels/sec
	Difference: 13760 (102%)

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 max amount of data (measured in megabytes per second) that can be transported across the external memory interface within a second. It's worked out by multiplying the card's interface width by the speed of its memory. If it uses DDR type memory, it must be multiplied by 2 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 AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied in one second. This is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the the core 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 fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.