Radeon HD 3870 X2 1GB vs Radeon HD 7790

Intro

Compare those specifications to the Radeon HD 7790, which comes with core speeds of 1000 MHz on the GPU, and 1500 MHz on the 1024 MB of GDDR5 RAM. It features 896 SPUs as well as 56 Texture Address Units and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon HD 3870 X2 1GB will be 50% faster than the Radeon HD 7790 in general, due to its greater data rate. (explain)

Radeon HD 3870 X2 1GB		144128 MB/sec
Radeon HD 7790		96000 MB/sec
	Difference: 48128 (50%)

Texel Rate

The Radeon HD 7790 will be much (more or less 112%) better at texture filtering than the Radeon HD 3870 X2 1GB. (explain)

Radeon HD 7790		56000 Mtexels/sec
Radeon HD 3870 X2 1GB		26400 Mtexels/sec
	Difference: 29600 (112%)

Pixel Rate

The Radeon HD 3870 X2 1GB is a lot (about 65%) better at anti-aliasing than the Radeon HD 7790, and will be able to handle higher resolutions without losing too much performance. (explain)

Radeon HD 3870 X2 1GB		26400 Mpixels/sec
Radeon HD 7790		16000 Mpixels/sec
	Difference: 10400 (65%)

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 max amount of data (in units of MB per second) that can be moved over the external memory interface in a second. It's worked out by multiplying the bus width by the speed of its memory. If it uses DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better 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 are processed per second. This figure is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly record to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.