GeForce 820M vs Radeon HD 4890 1GB

Intro

Compare all that to the Radeon HD 4890 1GB, which makes use of a 55 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 memory works at a frequency of 975 MHz on this card. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 175 Watts (1167%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4890 1GB is 680% faster than the GeForce 820M overall, due to its higher data rate. (explain)

Radeon HD 4890 1GB		124800 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 108800 (680%)

Texel Rate

The Radeon HD 4890 1GB should be quite a bit (approximately 248%) faster with regards to anisotropic filtering than the GeForce 820M. (explain)

Radeon HD 4890 1GB		40000 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 28496 (248%)

Pixel Rate

The Radeon HD 4890 1GB will be a lot (approximately 456%) faster with regards to FSAA than the GeForce 820M, and also will be capable of handling higher screen resolutions more effectively. (explain)

Radeon HD 4890 1GB		16000 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 13124 (456%)

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 max amount of data (measured in MB per second) that can be transferred over the external memory interface in a second. The number is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.