Radeon HD 4870 X2 vs Radeon HD 7790

Intro

Compare all of that to the Radeon HD 7790, which comes with a clock frequency of 1000 MHz and a GDDR5 memory frequency of 1500 MHz. It also uses a 128-bit bus, and makes use of a 28 nm design. It is made up of 896 SPUs, 56 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7790		85 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 265 Watts (312%)

Memory Bandwidth

In theory, the Radeon HD 4870 X2 is 140% faster than the Radeon HD 7790 in general, because of its greater bandwidth. (explain)

Radeon HD 4870 X2		230400 MB/sec
Radeon HD 7790		96000 MB/sec
	Difference: 134400 (140%)

Texel Rate

The Radeon HD 4870 X2 should be a little bit (approximately 7%) faster with regards to anisotropic filtering than the Radeon HD 7790. (explain)

Radeon HD 4870 X2		60000 Mtexels/sec
Radeon HD 7790		56000 Mtexels/sec
	Difference: 4000 (7%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 4870 X2 is the winner, by a large margin. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
Radeon HD 7790		16000 Mpixels/sec
	Difference: 8000 (50%)

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 maximum amount of information (counted in MB per second) that can be transported across the external memory interface in one second. It is calculated by multiplying the interface width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the most pixels the video card can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.