Geforce GTX 680 vs Radeon HD 3870 X2 1GB

Intro

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

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

The Geforce GTX 680 should in theory perform a lot faster than the Radeon HD 3870 X2 1GB overall. (explain)

Geforce GTX 680		192256 MB/sec
Radeon HD 3870 X2 1GB		144128 MB/sec
	Difference: 48128 (33%)

Texel Rate

The Geforce GTX 680 is a lot (about 388%) faster with regards to anisotropic filtering than the Radeon HD 3870 X2 1GB. (explain)

Geforce GTX 680		128768 Mtexels/sec
Radeon HD 3870 X2 1GB		26400 Mtexels/sec
	Difference: 102368 (388%)

Pixel Rate

The Geforce GTX 680 will be a lot (more or less 22%) more effective at FSAA than the Radeon HD 3870 X2 1GB, and should be capable of handling higher resolutions better. (explain)

Geforce GTX 680		32192 Mpixels/sec
Radeon HD 3870 X2 1GB		26400 Mpixels/sec
	Difference: 5792 (22%)

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 largest amount of data (in units of MB per second) that can be transferred across the external memory interface within a second. It's calculated by multiplying the bus width by its memory speed. In the case of DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster 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 can be applied per second. This is calculated by multiplying the total texture units of the card 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 per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.