GeForce 820M vs Radeon HD 4890 1GB

Intro

Compare that to the Radeon HD 4890 1GB, which has clock speeds of 1000 MHz on the GPU, and 975 MHz on the 1024 MB of GDDR5 RAM. It features 800(160x5) SPUs along with 40 TAUs 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

Performance-wise, the Radeon HD 4890 1GB should theoretically be quite a bit superior to the GeForce 820M in general. (explain)

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

Texel Rate

The Radeon HD 4890 1GB is quite a bit (about 248%) faster with regards to AF 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 is a lot (about 456%) better at AA than the GeForce 820M, and also should be capable of handling higher 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: Memory bandwidth is the maximum amount of information (in units of MB per second) that can be transferred past the external memory interface in one second. It is calculated by multiplying the interface width by its memory speed. If the card has DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.