GeForce GTX 660 vs Radeon R5 M255

Intro

Compare those specs to the Radeon R5 M255, which uses a 28 nm design. AMD has set the core speed at 940 MHz. The DDR3 RAM runs at a speed of 1000 MHz on this model. It features 320 SPUs as well as 20 TAUs and 8 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

In theory, the GeForce GTX 660 is 801% faster than the Radeon R5 M255 overall, due to its higher data rate. (explain)

GeForce GTX 660		144192 MB/sec
Radeon R5 M255		16000 MB/sec
	Difference: 128192 (801%)

Texel Rate

The GeForce GTX 660 should be quite a bit (more or less 317%) better at AF than the Radeon R5 M255. (explain)

GeForce GTX 660		78400 Mtexels/sec
Radeon R5 M255		18800 Mtexels/sec
	Difference: 59600 (317%)

Pixel Rate

The GeForce GTX 660 is a lot (more or less 213%) faster with regards to full screen anti-aliasing than the Radeon R5 M255, and should be able to handle higher screen resolutions more effectively. (explain)

GeForce GTX 660		23520 Mpixels/sec
Radeon R5 M255		7520 Mpixels/sec
	Difference: 16000 (213%)

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 max amount of data (in units of megabytes per second) that can be transported across the external memory interface in one second. It is calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR RAM, 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 anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number 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 by the core clock speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video 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 amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.