GeForce 820M vs Radeon HD 4750

Intro

Compare all of that to the Radeon HD 4750, which has a GPU core clock speed of 730 MHz, and 512 MB of GDDR5 memory set to run at 800 MHz through a 128-bit bus. It also is comprised of 640(128x5) Stream Processors, 32 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
Radeon HD 4750		75 Watts
	Difference: 60 Watts (400%)

Memory Bandwidth

The Radeon HD 4750 should in theory perform quite a bit faster than the GeForce 820M in general. (explain)

Radeon HD 4750		51200 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 35200 (220%)

Texel Rate

The Radeon HD 4750 is a lot (more or less 103%) more effective at texture filtering than the GeForce 820M. (explain)

Radeon HD 4750		23360 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 11856 (103%)

Pixel Rate

The Radeon HD 4750 should be a lot (approximately 306%) better at anti-aliasing than the GeForce 820M, and should be capable of handling higher screen resolutions without slowing down too much. (explain)

Radeon HD 4750		11680 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 8804 (306%)

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 largest amount of information (measured in megabytes per second) that can be moved past the external memory interface within a second. The number is calculated by multiplying the card's interface width by its memory clock speed. If the card has DDR RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, 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 texture map elements (texels) that are applied per second. This number is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video 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 that the graphics chip can possibly record to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.