GeForce GT 420 vs Radeon R5 M255

Intro

Compare all that to the Radeon R5 M255, which has core clock speeds of 940 MHz on the GPU, and 1000 MHz on the 2048 MB of DDR3 memory. It features 320 SPUs as well as 20 Texture Address Units and 8 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

The GeForce GT 420 should theoretically perform much faster than the Radeon R5 M255 in general. (explain)

GeForce GT 420		28800 MB/sec
Radeon R5 M255		16000 MB/sec
	Difference: 12800 (80%)

Texel Rate

The Radeon R5 M255 will be a lot (about 236%) better at AF than the GeForce GT 420. (explain)

Radeon R5 M255		18800 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 13200 (236%)

Pixel Rate

The Radeon R5 M255 should be quite a bit (about 169%) more effective at anti-aliasing than the GeForce GT 420, and also should be able to handle higher screen resolutions without slowing down too much. (explain)

Radeon R5 M255		7520 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 4720 (169%)

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 (measured in megabytes per second) that can be transferred past the external memory interface within a second. The number is calculated by multiplying the card's bus width by the speed of its memory. If it uses DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This number is worked out by multiplying the total amount of texture units of the card by the core 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 processed in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few 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.