Radeon HD 4670 512MB vs Radeon R5 M255

Intro

Compare those specifications to the Radeon R5 M255, which comes with core clock speeds of 940 MHz on the GPU, and 1000 MHz on the 2048 MB of DDR3 memory. It features 320 SPUs along with 20 Texture Address Units and 8 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

The Radeon HD 4670 512MB, in theory, should be a lot faster than the Radeon R5 M255 overall. (explain)

Radeon HD 4670 512MB		32000 MB/sec
Radeon R5 M255		16000 MB/sec
	Difference: 16000 (100%)

Texel Rate

The Radeon HD 4670 512MB is a lot (about 28%) more effective at anisotropic filtering than the Radeon R5 M255. (explain)

Radeon HD 4670 512MB		24000 Mtexels/sec
Radeon R5 M255		18800 Mtexels/sec
	Difference: 5200 (28%)

Pixel Rate

The Radeon R5 M255 should be quite a bit (more or less 25%) more effective at full screen anti-aliasing than the Radeon HD 4670 512MB, and also able to handle higher screen resolutions without losing too much performance. (explain)

Radeon R5 M255		7520 Mpixels/sec
Radeon HD 4670 512MB		6000 Mpixels/sec
	Difference: 1520 (25%)

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 MB per second) that can be transferred past the external memory interface in a second. It's worked out by multiplying the bus width by its memory speed. If the card has DDR memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the 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 texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher 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 a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.