GeForce 9800 GX2 vs Radeon HD 4830 1GB

Intro

Compare all of that to the Radeon HD 4830 1GB, which comes with a core clock speed of 575 MHz and a GDDR4 memory speed of 900 MHz. It also makes use of a 256-bit memory bus, and makes use of a 55 nm design. It is comprised of 640(128x5) SPUs, 32 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 4830 1GB		95 Watts
GeForce 9800 GX2		197 Watts
	Difference: 102 Watts (107%)

Memory Bandwidth

Performance-wise, the GeForce 9800 GX2 should theoretically be quite a bit superior to the Radeon HD 4830 1GB in general. (explain)

GeForce 9800 GX2		128000 MB/sec
Radeon HD 4830 1GB		57600 MB/sec
	Difference: 70400 (122%)

Texel Rate

The GeForce 9800 GX2 should be much (approximately 317%) better at anisotropic filtering than the Radeon HD 4830 1GB. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
Radeon HD 4830 1GB		18400 Mtexels/sec
	Difference: 58400 (317%)

Pixel Rate

The GeForce 9800 GX2 will be a lot (approximately 109%) faster with regards to anti-aliasing than the Radeon HD 4830 1GB, and capable of handling higher screen resolutions without slowing down too much. (explain)

GeForce 9800 GX2		19200 Mpixels/sec
Radeon HD 4830 1GB		9200 Mpixels/sec
	Difference: 10000 (109%)

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 (measured in MB per second) that can be transferred over the external memory interface within a second. It's calculated by multiplying the card's interface width by its memory clock speed. If the card has DDR type memory, it must be multiplied by 2 once again. If it uses 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 are applied in one second. This is worked out 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 graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. The figure is calculated 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 filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.