GeForce GTX 660 Ti vs Radeon HD 7990

Intro

Compare all of that to the Radeon HD 7990, which makes use of a 28 nm design. AMD has set the core speed at 950 MHz. The GDDR5 RAM is set to run at a frequency of 1500 MHz on this model. It features 2048 SPUs along with 128 TAUs and 32 ROPs.

Display Graphs

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Benchmarks

These are real-world performance benchmarks that were submitted by Hardware Compare users. The scores seen here are the average of all benchmarks submitted for each respective test and hardware.

3DMark Fire Strike Graphics Score

Radeon HD 7990		15520 points
GeForce GTX 660 Ti		6013 points
	Difference: 9507 (158%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 660 Ti		150 Watts
Radeon HD 7990		375 Watts
	Difference: 225 Watts (150%)

Memory Bandwidth

Performance-wise, the Radeon HD 7990 should theoretically be a lot better than the GeForce GTX 660 Ti in general. (explain)

Radeon HD 7990		576000 MB/sec
GeForce GTX 660 Ti		144000 MB/sec
	Difference: 432000 (300%)

Texel Rate

The Radeon HD 7990 will be much (approximately 137%) faster with regards to anisotropic filtering than the GeForce GTX 660 Ti. (explain)

Radeon HD 7990		243200 Mtexels/sec
GeForce GTX 660 Ti		102480 Mtexels/sec
	Difference: 140720 (137%)

Pixel Rate

The Radeon HD 7990 should be a lot (more or less 177%) better at FSAA than the GeForce GTX 660 Ti, and should be able to handle higher resolutions while still performing well. (explain)

Radeon HD 7990		60800 Mpixels/sec
GeForce GTX 660 Ti		21960 Mpixels/sec
	Difference: 38840 (177%)

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 max amount of data (counted in MB per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. If it uses DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.