Radeon HD 3870 1GB vs Radeon HD 3870 X2 1GB

Intro

Compare those specifications to the Radeon HD 3870 X2 1GB, which has a core clock speed of 825 MHz and a GDDR4 memory frequency of 1126 MHz. It also features a 256-bit memory bus, and uses a 55 nm design. It is comprised of 320(64x5) SPUs, 16 TAUs, and 16 Raster Operation Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Memory Bandwidth

As far as performance goes, the Radeon HD 3870 X2 1GB should in theory be quite a bit superior to the Radeon HD 3870 1GB in general. (explain)

Radeon HD 3870 X2 1GB		144128 MB/sec
Radeon HD 3870 1GB		72000 MB/sec
	Difference: 72128 (100%)

Texel Rate

The Radeon HD 3870 X2 1GB is a lot (approximately 113%) more effective at texture filtering than the Radeon HD 3870 1GB. (explain)

Radeon HD 3870 X2 1GB		26400 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 14000 (113%)

Pixel Rate

The Radeon HD 3870 X2 1GB is quite a bit (more or less 113%) better at FSAA than the Radeon HD 3870 1GB, and will be able to handle higher screen resolutions while still performing well. (explain)

Radeon HD 3870 X2 1GB		26400 Mpixels/sec
Radeon HD 3870 1GB		12400 Mpixels/sec
	Difference: 14000 (113%)

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 maximum amount of data (in units of MB per second) that can be transferred across the external memory interface in a second. It is calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. 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 texture map elements (texels) that are applied per second. This number is worked out by multiplying the total texture units by the core clock speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Raster Operations Pipelines by the clock 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 output rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.