GeForce GTX 280 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 speed of 1126 MHz. It also makes use of a 256-bit bus, and makes use of 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 Radeon HD 3870 X2 1GB should in theory perform a small bit faster than the GeForce GTX 280 overall. (explain)

Radeon HD 3870 X2 1GB		144128 MB/sec
GeForce GTX 280		141696 MB/sec
	Difference: 2432 (2%)

Texel Rate

The GeForce GTX 280 should be quite a bit (about 82%) more effective at AF than the Radeon HD 3870 X2 1GB. (explain)

GeForce GTX 280		48160 Mtexels/sec
Radeon HD 3870 X2 1GB		26400 Mtexels/sec
	Difference: 21760 (82%)

Pixel Rate

The Radeon HD 3870 X2 1GB is a lot (about 37%) more effective at AA than the GeForce GTX 280, and should be able to handle higher resolutions without slowing down too much. (explain)

Radeon HD 3870 X2 1GB		26400 Mpixels/sec
GeForce GTX 280		19264 Mpixels/sec
	Difference: 7136 (37%)

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 information (in units of megabytes per second) that can be transported over the external memory interface in one second. It's worked out by multiplying the bus width by its memory speed. If the card has DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the faster 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 in one second. This is calculated by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called 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.