GeForce GTX 280 vs Radeon HD 3870 X2 1GB

Intro

Compare all of that to the Radeon HD 3870 X2 1GB, which features a core clock speed of 825 MHz and a GDDR4 memory frequency of 1126 MHz. It also makes use of a 256-bit memory bus, and uses a 55 nm design. It is made up of 320(64x5) SPUs, 16 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon HD 3870 X2 1GB should be 2% quicker than the GeForce GTX 280 overall, because of its greater bandwidth. (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 much (approximately 82%) better 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

If using a high resolution is important to you, then the Radeon HD 3870 X2 1GB is the winner, and very much so. (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: Bandwidth is the maximum amount of information (in units of megabytes per second) that can be transferred past the external memory interface in one second. It is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, 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 are applied per second. This is calculated 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 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 the graphics card could possibly record to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.