GeForce 920M vs Radeon HD 4870 512MB

Intro

Compare that to the Radeon HD 4870 512MB, which comes with GPU core speed of 750 MHz, and 512 MB of GDDR5 memory running at 900 MHz through a 256-bit bus. It also features 800(160x5) Stream Processors, 40 TAUs, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon HD 4870 512MB is 700% faster than the GeForce 920M overall, because of its higher bandwidth. (explain)

Radeon HD 4870 512MB		115200 MB/sec
GeForce 920M		14400 MB/sec
	Difference: 100800 (700%)

Texel Rate

The GeForce 920M should be a small bit (more or less 2%) better at AF than the Radeon HD 4870 512MB. (explain)

GeForce 920M		30528 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 528 (2%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 4870 512MB is superior to the GeForce 920M, by far. (explain)

Radeon HD 4870 512MB		12000 Mpixels/sec
GeForce 920M		7632 Mpixels/sec
	Difference: 4368 (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: Bandwidth is the maximum amount of information (counted in MB per second) that can be transferred past the external memory interface in a second. It's worked out by multiplying the interface width by its memory speed. If it uses DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to its local memory in one 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 outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.