Radeon HD 4650 512MB vs Radeon R5 M255

Intro

Compare those specifications to the Radeon R5 M255, which features a GPU core clock speed of 940 MHz, and 2048 MB of DDR3 RAM running at 1000 MHz through a 64-bit bus. It also features 320 Stream Processors, 20 Texture Address Units, and 8 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

Both cards have exactly the same memory bandwidth, so theoretically they should perform exactly the same. (explain)

Texel Rate

The Radeon HD 4650 512MB should be a small bit (more or less 2%) more effective at anisotropic filtering than the Radeon R5 M255. (explain)

Radeon HD 4650 512MB		19200 Mtexels/sec
Radeon R5 M255		18800 Mtexels/sec
	Difference: 400 (2%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon R5 M255 is a better choice, by far. (explain)

Radeon R5 M255		7520 Mpixels/sec
Radeon HD 4650 512MB		4800 Mpixels/sec
	Difference: 2720 (57%)

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 megabytes per second) that can be moved over the external memory interface in one second. It's calculated by multiplying the card's interface width by its memory clock speed. In the case of 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, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number 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, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.