GeForce GT 640 DDR3 vs Radeon R5 M255

Intro

Compare all of that to the Radeon R5 M255, which comes with GPU core speed of 940 MHz, and 2048 MB of DDR3 RAM running at 1000 MHz through a 64-bit bus. It also is made up of 320 Stream Processors, 20 TAUs, and 8 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

As far as performance goes, the GeForce GT 640 DDR3 should theoretically be a lot superior to the Radeon R5 M255 in general. (explain)

GeForce GT 640 DDR3		57024 MB/sec
Radeon R5 M255		16000 MB/sec
	Difference: 41024 (256%)

Texel Rate

The GeForce GT 640 DDR3 will be much (about 53%) faster with regards to texture filtering than the Radeon R5 M255. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
Radeon R5 M255		18800 Mtexels/sec
	Difference: 10000 (53%)

Pixel Rate

If using high levels of AA is important to you, then the GeForce GT 640 DDR3 is superior to the Radeon R5 M255, by a large margin. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
Radeon R5 M255		7520 Mpixels/sec
	Difference: 6880 (91%)

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 information (counted in megabytes per second) that can be transported past the external memory interface in a second. It is worked out by multiplying the bus width by its memory speed. If it uses DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.