GeForce GTX 660 Ti vs Radeon HD 4870 2GB

Intro

Compare all that to the Radeon HD 4870 2GB, which has a clock speed of 750 MHz and a GDDR5 memory frequency of 900 MHz. It also features a 256-bit bus, and uses a 55 nm design. It is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Both cards have the same power consumption.

Memory Bandwidth

In theory, the GeForce GTX 660 Ti will be 25% faster than the Radeon HD 4870 2GB in general, because of its greater bandwidth. (explain)

GeForce GTX 660 Ti		144000 MB/sec
Radeon HD 4870 2GB		115200 MB/sec
	Difference: 28800 (25%)

Texel Rate

The GeForce GTX 660 Ti will be much (about 242%) more effective at AF than the Radeon HD 4870 2GB. (explain)

GeForce GTX 660 Ti		102480 Mtexels/sec
Radeon HD 4870 2GB		30000 Mtexels/sec
	Difference: 72480 (242%)

Pixel Rate

The GeForce GTX 660 Ti will be much (approximately 83%) more effective at AA than the Radeon HD 4870 2GB, and also will be capable of handling higher resolutions without losing too much performance. (explain)

GeForce GTX 660 Ti		21960 Mpixels/sec
Radeon HD 4870 2GB		12000 Mpixels/sec
	Difference: 9960 (83%)

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 maximum amount of data (in units of megabytes per second) that can be moved across the external memory interface in a second. It is worked out by multiplying the bus width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This figure is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the graphics 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 the graphics card could possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated 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 outputting the pixels (image) to the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.