GeForce 825M vs GeForce GTX 970M

Intro

Compare those specs to the GeForce GTX 970M, which uses a 28 nm design. nVidia has clocked the core frequency at 924 MHz. The GDDR5 memory works at a frequency of 1000 MHz on this specific card. It features 1280 SPUs as well as 80 Texture Address Units and 48 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 825M		33 Watts
GeForce GTX 970M		75 Watts
	Difference: 42 Watts (127%)

Memory Bandwidth

Theoretically speaking, the GeForce GTX 970M should be 567% quicker than the GeForce 825M overall, because of its greater data rate. (explain)

GeForce GTX 970M		96000 MB/sec
GeForce 825M		14400 MB/sec
	Difference: 81600 (567%)

Texel Rate

The GeForce GTX 970M is much (more or less 444%) better at AF than the GeForce 825M. (explain)

GeForce GTX 970M		73920 Mtexels/sec
GeForce 825M		13600 Mtexels/sec
	Difference: 60320 (444%)

Pixel Rate

The GeForce GTX 970M will be much (about 552%) better at anti-aliasing than the GeForce 825M, and will be capable of handling higher resolutions while still performing well. (explain)

GeForce GTX 970M		44352 Mpixels/sec
GeForce 825M		6800 Mpixels/sec
	Difference: 37552 (552%)

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 data (measured in MB per second) that can be moved across the external memory interface in a second. It's calculated by multiplying the card's interface width by its memory speed. In the case of DDR RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. 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 amount of texture map elements (texels) that are applied per second. This is calculated by multiplying the total number 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 handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels that 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 Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.