GeForce 820M vs GeForce GT 310

Intro

Compare all of that to the GeForce GT 310, which uses a 40 nm design. nVidia has clocked the core speed at 589 MHz. The DDR2 memory is set to run at a speed of 1000 MHz on this particular model. It features 16 SPUs along with 8 Texture Address Units and 4 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
GeForce GT 310		31 Watts
	Difference: 16 Watts (107%)

Memory Bandwidth

Both cards have exactly the same bandwidth, so in theory they should perform exactly the same. (explain)

Texel Rate

The GeForce 820M should be much (about 144%) better at texture filtering than the GeForce GT 310. (explain)

GeForce 820M		11504 Mtexels/sec
GeForce GT 310		4712 Mtexels/sec
	Difference: 6792 (144%)

Pixel Rate

The GeForce 820M will be a lot (about 22%) more effective at anti-aliasing than the GeForce GT 310, and also capable of handling higher resolutions more effectively. (explain)

GeForce 820M		2876 Mpixels/sec
GeForce GT 310		2356 Mpixels/sec
	Difference: 520 (22%)

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 (in units of MB per second) that can be moved past the external memory interface in a second. It's calculated by multiplying the interface width by its memory clock speed. If it uses DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.