GeForce 820M vs Radeon HD 5770

Intro

Compare all that to the Radeon HD 5770, which has core clock speeds of 850 MHz on the GPU, and 1200 MHz on the 1024 MB of GDDR5 memory. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
Radeon HD 5770		108 Watts
	Difference: 93 Watts (620%)

Memory Bandwidth

Theoretically, the Radeon HD 5770 should perform quite a bit faster than the GeForce 820M in general. (explain)

Radeon HD 5770		76800 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 60800 (380%)

Texel Rate

The Radeon HD 5770 should be much (more or less 196%) more effective at AF than the GeForce 820M. (explain)

Radeon HD 5770		34000 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 22496 (196%)

Pixel Rate

The Radeon HD 5770 is quite a bit (more or less 373%) faster with regards to anti-aliasing than the GeForce 820M, and also should be able to handle higher resolutions better. (explain)

Radeon HD 5770		13600 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 10724 (373%)

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 transferred over the external memory interface in a second. It is calculated by multiplying the card's bus width by the speed of its memory. In the case of DDR RAM, the result should be multiplied by 2 again. If it uses 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, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes 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, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.