GeForce 9800 GX2 vs Radeon HD 3870 1GB

Intro

Compare those specs to the Radeon HD 3870 1GB, which features a core clock speed of 775 MHz and a GDDR4 memory speed of 1125 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 TAUs, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 1GB		106 Watts
GeForce 9800 GX2		197 Watts
	Difference: 91 Watts (86%)

Memory Bandwidth

The GeForce 9800 GX2 should in theory be much faster than the Radeon HD 3870 1GB overall. (explain)

GeForce 9800 GX2		128000 MB/sec
Radeon HD 3870 1GB		72000 MB/sec
	Difference: 56000 (78%)

Texel Rate

The GeForce 9800 GX2 will be a lot (more or less 519%) faster with regards to AF than the Radeon HD 3870 1GB. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 64400 (519%)

Pixel Rate

The GeForce 9800 GX2 should be much (approximately 55%) faster with regards to AA than the Radeon HD 3870 1GB, and will be able to handle higher resolutions while still performing well. (explain)

GeForce 9800 GX2		19200 Mpixels/sec
Radeon HD 3870 1GB		12400 Mpixels/sec
	Difference: 6800 (55%)

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 data (counted in megabytes per second) that can be moved over the external memory interface in one second. It's worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum 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 clock speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on many 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.