Radeon HD 7790 vs Radeon R5 M255

Intro

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

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon HD 7790 will be 500% quicker than the Radeon R5 M255 in general, due to its greater bandwidth. (explain)

Radeon HD 7790		96000 MB/sec
Radeon R5 M255		16000 MB/sec
	Difference: 80000 (500%)

Texel Rate

The Radeon HD 7790 will be much (about 198%) faster with regards to texture filtering than the Radeon R5 M255. (explain)

Radeon HD 7790		56000 Mtexels/sec
Radeon R5 M255		18800 Mtexels/sec
	Difference: 37200 (198%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon HD 7790 is a better choice, by a large margin. (explain)

Radeon HD 7790		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: Bandwidth is the maximum amount of information (measured in megabytes per second) that can be transported across the external memory interface within a second. It is worked out by multiplying the bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on lots of 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.