GeForce GT 420 vs GeForce GTX 980

Intro

Compare those specifications to the GeForce GTX 980, which uses a 28 nm design. nVidia has set the core speed at 1126 MHz. The GDDR5 RAM is set to run at a speed of 1750 MHz on this model. It features 2048 SPUs as well as 128 Texture Address Units and 64 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
GeForce GTX 980		165 Watts
	Difference: 115 Watts (230%)

Memory Bandwidth

Performance-wise, the GeForce GTX 980 should theoretically be quite a bit better than the GeForce GT 420 in general. (explain)

GeForce GTX 980		224000 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 195200 (678%)

Texel Rate

The GeForce GTX 980 should be a lot (about 2474%) faster with regards to anisotropic filtering than the GeForce GT 420. (explain)

GeForce GTX 980		144128 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 138528 (2474%)

Pixel Rate

The GeForce GTX 980 is much (about 2474%) more effective at full screen anti-aliasing than the GeForce GT 420, and also will be capable of handling higher resolutions more effectively. (explain)

GeForce GTX 980		72064 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 69264 (2474%)

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: Bandwidth is the max amount of data (counted in megabytes per second) that can be moved past the external memory interface in one second. The number is calculated by multiplying the interface width by its memory clock speed. In the case of DDR RAM, it must be multiplied by 2 again. If 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 are processed per second. This figure is worked out by multiplying the total number of texture units by the core speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the core clock speed. 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 fill rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.