GeForce 820M vs GeForce GTS 250 512MB

Intro

Compare those specifications to the GeForce GTS 250 512MB, which features clock speeds of 738 MHz on the GPU, and 1100 MHz on the 512 MB of GDDR3 memory. It features 128 SPUs along with 64 TAUs and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
GeForce GTS 250 512MB		145 Watts
	Difference: 130 Watts (867%)

Memory Bandwidth

In theory, the GeForce GTS 250 512MB will be 340% faster than the GeForce 820M overall, due to its higher data rate. (explain)

GeForce GTS 250 512MB		70400 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 54400 (340%)

Texel Rate

The GeForce GTS 250 512MB should be a lot (more or less 311%) better at anisotropic filtering than the GeForce 820M. (explain)

GeForce GTS 250 512MB		47232 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 35728 (311%)

Pixel Rate

If running with a high screen resolution is important to you, then the GeForce GTS 250 512MB is a better choice, and very much so. (explain)

GeForce GTS 250 512MB		11808 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 8932 (311%)

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 (counted in MB per second) that can be moved over the external memory interface in one second. It is calculated by multiplying the bus width by its memory speed. If it uses DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

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