GeForce 9800 GX2 vs Radeon HD 3870 1GB

Intro

Compare that to the Radeon HD 3870 1GB, which features a clock frequency of 775 MHz and a GDDR4 memory frequency of 1125 MHz. It also uses a 256-bit bus, and makes use of a 55 nm design. It features 320(64x5) SPUs, 16 Texture Address Units, 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

As far as performance goes, the GeForce 9800 GX2 should in theory be much better 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 should 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 will be a lot (approximately 55%) more effective at FSAA than the Radeon HD 3870 1GB, and also should be able to handle higher resolutions without losing too much performance. (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 (measured in MB per second) that can be transferred over the external memory interface in a second. The number is calculated by multiplying the bus width by its memory speed. If it uses DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This number is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.