GeForce GTX 660 Ti vs Radeon HD 4890 2GB

Intro

Compare that to the Radeon HD 4890 2GB, which comes with a clock frequency of 1000 MHz and a GDDR5 memory speed of 975 MHz. It also makes use of a 256-bit memory bus, and makes use of a 55 nm design. It is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 660 Ti		150 Watts
Radeon HD 4890 2GB		190 Watts
	Difference: 40 Watts (27%)

Memory Bandwidth

As far as performance goes, the GeForce GTX 660 Ti should in theory be a small bit superior to the Radeon HD 4890 2GB overall. (explain)

GeForce GTX 660 Ti		144000 MB/sec
Radeon HD 4890 2GB		124800 MB/sec
	Difference: 19200 (15%)

Texel Rate

The GeForce GTX 660 Ti will be a lot (approximately 156%) more effective at anisotropic filtering than the Radeon HD 4890 2GB. (explain)

GeForce GTX 660 Ti		102480 Mtexels/sec
Radeon HD 4890 2GB		40000 Mtexels/sec
	Difference: 62480 (156%)

Pixel Rate

If running with a high screen resolution is important to you, then the GeForce GTX 660 Ti is the winner, by far. (explain)

GeForce GTX 660 Ti		21960 Mpixels/sec
Radeon HD 4890 2GB		16000 Mpixels/sec
	Difference: 5960 (37%)

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 information (measured in MB per second) that can be moved past the external memory interface within a second. The number is worked out by multiplying the bus width by the speed of its memory. If the card has DDR RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total texture units by the core clock 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 per second.

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines 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 rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.