GeForce GTX 285 1GB vs Radeon HD 7990

Intro

Compare all of that to the Radeon HD 7990, which has GPU clock speed of 950 MHz, and 3072 MB of GDDR5 RAM set to run at 1500 MHz through a 384-bit bus. It also is made up of 2048 SPUs, 128 TAUs, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 285 1GB		204 Watts
Radeon HD 7990		375 Watts
	Difference: 171 Watts (84%)

Memory Bandwidth

Theoretically, the Radeon HD 7990 should be much faster than the GeForce GTX 285 1GB overall. (explain)

Radeon HD 7990		576000 MB/sec
GeForce GTX 285 1GB		158976 MB/sec
	Difference: 417024 (262%)

Texel Rate

The Radeon HD 7990 should be a lot (more or less 369%) more effective at AF than the GeForce GTX 285 1GB. (explain)

Radeon HD 7990		243200 Mtexels/sec
GeForce GTX 285 1GB		51840 Mtexels/sec
	Difference: 191360 (369%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 7990 is a better choice, by a large margin. (explain)

Radeon HD 7990		60800 Mpixels/sec
GeForce GTX 285 1GB		20736 Mpixels/sec
	Difference: 40064 (193%)

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 (counted in MB per second) that can be transferred past the external memory interface in a second. The number is worked out by multiplying the interface width by the speed of its memory. If the card has DDR RAM, the result 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 anti-aliasing, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.