Radeon HD 4650 512MB vs Radeon R5 M255

Intro

Compare all that to the Radeon R5 M255, which has a clock frequency of 940 MHz and a DDR3 memory frequency of 1000 MHz. It also makes use of a 64-bit bus, and makes use of a 28 nm design. It features 320 SPUs, 20 Texture Address Units, and 8 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Both cards have the exact same bandwidth, so in theory they should have identical performance. (explain)

Texel Rate

The Radeon HD 4650 512MB should be a bit (approximately 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

The Radeon R5 M255 is quite a bit (more or less 57%) faster with regards to anti-aliasing than the Radeon HD 4650 512MB, and also able to handle higher resolutions without slowing down too much. (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 data (measured in MB per second) that can be moved over the external memory interface in a second. The number is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, 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 number of texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, the better the 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 most pixels the video card can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.