GeForce GT 420 vs GeForce GTX 660

Intro

Compare those specifications to the GeForce GTX 660, which features core speeds of 980 MHz on the GPU, and 1502 MHz on the 2048 MB of GDDR5 memory. It features 960 SPUs as well as 80 TAUs and 24 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
GeForce GTX 660		140 Watts
	Difference: 90 Watts (180%)

Memory Bandwidth

As far as performance goes, the GeForce GTX 660 should theoretically be a lot better than the GeForce GT 420 overall. (explain)

GeForce GTX 660		144192 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 115392 (401%)

Texel Rate

The GeForce GTX 660 will be quite a bit (approximately 1300%) better at texture filtering than the GeForce GT 420. (explain)

GeForce GTX 660		78400 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 72800 (1300%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the GeForce GTX 660 is superior to the GeForce GT 420, and very much so. (explain)

GeForce GTX 660		23520 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 20720 (740%)

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

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher this number, the better the graphics 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 amount of pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.