Radeon HD 3870 X2 1GB vs Radeon HD 7870 XT

Intro

Compare those specs to the Radeon HD 7870 XT, which uses a 28 nm design. AMD has clocked the core speed at 925 MHz. The GDDR5 RAM works at a speed of 1500 MHz on this model. It features 1536 SPUs as well as 96 TAUs and 32 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

In theory, the Radeon HD 7870 XT should perform a lot faster than the Radeon HD 3870 X2 1GB overall. (explain)

Radeon HD 7870 XT		192000 MB/sec
Radeon HD 3870 X2 1GB		144128 MB/sec
	Difference: 47872 (33%)

Texel Rate

The Radeon HD 7870 XT should be quite a bit (about 236%) more effective at texture filtering than the Radeon HD 3870 X2 1GB. (explain)

Radeon HD 7870 XT		88800 Mtexels/sec
Radeon HD 3870 X2 1GB		26400 Mtexels/sec
	Difference: 62400 (236%)

Pixel Rate

The Radeon HD 7870 XT will be a small bit (about 12%) more effective at full screen anti-aliasing than the Radeon HD 3870 X2 1GB, and also will be capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 7870 XT		29600 Mpixels/sec
Radeon HD 3870 X2 1GB		26400 Mpixels/sec
	Difference: 3200 (12%)

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 max amount of information (counted in megabytes per second) that can be transported over the external memory interface in one second. The number is worked out by multiplying the card's bus width by its memory clock speed. In the case of DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better 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 number of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card 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 Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.