GeForce GTX 660 Ti vs Radeon HD 4790

Intro

Compare those specs to the Radeon HD 4790, which comes with core speeds of 600 MHz on the GPU, and 800 MHz on the 512 MB of GDDR5 memory. It features 640(128x5) SPUs as well as 32 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Performance-wise, the GeForce GTX 660 Ti should in theory be much better than the Radeon HD 4790 in general. (explain)

GeForce GTX 660 Ti		144000 MB/sec
Radeon HD 4790		102400 MB/sec
	Difference: 41600 (41%)

Texel Rate

The GeForce GTX 660 Ti will be much (about 434%) more effective at anisotropic filtering than the Radeon HD 4790. (explain)

GeForce GTX 660 Ti		102480 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 83280 (434%)

Pixel Rate

The GeForce GTX 660 Ti should be a lot (more or less 129%) better at full screen anti-aliasing than the Radeon HD 4790, and also should be able to handle higher screen resolutions while still performing well. (explain)

GeForce GTX 660 Ti		21960 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 12360 (129%)

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.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the largest amount of data (measured in megabytes per second) that can be transported over the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory speed. If it uses DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total 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 amount of pixels the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.