Radeon HD 4890 1GB vs Radeon R5 M255

Intro

Compare all of that to the Radeon R5 M255, which makes use of a 28 nm design. AMD has clocked the core speed at 940 MHz. The DDR3 RAM is set to run at a speed of 1000 MHz on this model. It features 320 SPUs along with 20 Texture Address Units and 8 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon HD 4890 1GB should be much faster than the Radeon R5 M255 overall. (explain)

Radeon HD 4890 1GB		124800 MB/sec
Radeon R5 M255		16000 MB/sec
	Difference: 108800 (680%)

Texel Rate

The Radeon HD 4890 1GB is much (approximately 113%) more effective at anisotropic filtering than the Radeon R5 M255. (explain)

Radeon HD 4890 1GB		40000 Mtexels/sec
Radeon R5 M255		18800 Mtexels/sec
	Difference: 21200 (113%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon HD 4890 1GB is superior to the Radeon R5 M255, by a large margin. (explain)

Radeon HD 4890 1GB		16000 Mpixels/sec
Radeon R5 M255		7520 Mpixels/sec
	Difference: 8480 (113%)

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 max amount of information (counted in MB per second) that can be moved over the external memory interface in a second. It is worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly record to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs 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 is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.