GeForce GTX 660 Ti vs Radeon R9 M390X

Intro

Compare all of that to the Radeon R9 M390X, which has GPU clock speed of 723 MHz, and 4096 MB of GDDR5 memory running at 1250 MHz through a 256-bit bus. It also is made up of 2048 SPUs, 128 TAUs, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M390X		125 Watts
GeForce GTX 660 Ti		150 Watts
	Difference: 25 Watts (20%)

Memory Bandwidth

The Radeon R9 M390X, in theory, should perform just a bit faster than the GeForce GTX 660 Ti overall. (explain)

Radeon R9 M390X		160000 MB/sec
GeForce GTX 660 Ti		144000 MB/sec
	Difference: 16000 (11%)

Texel Rate

The GeForce GTX 660 Ti is a small bit (about 11%) better at anisotropic filtering than the Radeon R9 M390X. (explain)

GeForce GTX 660 Ti		102480 Mtexels/sec
Radeon R9 M390X		92544 Mtexels/sec
	Difference: 9936 (11%)

Pixel Rate

If using a high resolution is important to you, then the Radeon R9 M390X is superior to the GeForce GTX 660 Ti, but not by far. (explain)

Radeon R9 M390X		23136 Mpixels/sec
GeForce GTX 660 Ti		21960 Mpixels/sec
	Difference: 1176 (5%)

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: Bandwidth is the largest amount of data (measured in MB per second) that can be moved over the external memory interface in a second. It is worked out by multiplying the bus width by its memory speed. If it uses DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster 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 processed in one second. This is calculated by multiplying the total texture units 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 in a second.

Pixel Rate: Pixel rate is the most pixels the video card can possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.