GeForce 820M vs Radeon HD 5870

Intro

Compare all of that to the Radeon HD 5870, which comes with a core clock speed of 850 MHz and a GDDR5 memory frequency of 1200 MHz. It also uses a 256-bit memory bus, and makes use of a 40 nm design. It features 1600(320x5) SPUs, 80 TAUs, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
Radeon HD 5870		188 Watts
	Difference: 173 Watts (1153%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 5870 will be 860% quicker than the GeForce 820M in general, because of its greater data rate. (explain)

Radeon HD 5870		153600 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 137600 (860%)

Texel Rate

The Radeon HD 5870 is much (about 491%) better at texture filtering than the GeForce 820M. (explain)

Radeon HD 5870		68000 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 56496 (491%)

Pixel Rate

The Radeon HD 5870 is quite a bit (more or less 846%) faster with regards to AA than the GeForce 820M, and should be able to handle higher screen resolutions without losing too much performance. (explain)

Radeon HD 5870		27200 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 24324 (846%)

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 data (measured in megabytes per second) that can be transferred past the external memory interface within a second. The number is calculated by multiplying the bus width by the speed of its memory. If the card has DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly record to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.