GeForce GT 420 vs GeForce GTX 580

Intro

Compare all that to the GeForce GTX 580, which has a core clock frequency of 772 MHz and a GDDR5 memory speed of 1002 MHz. It also makes use of a 384-bit bus, and makes use of a 40 nm design. It is comprised of 512 SPUs, 64 Texture Address Units, and 48 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
GeForce GTX 580		244 Watts
	Difference: 194 Watts (388%)

Memory Bandwidth

Performance-wise, the GeForce GTX 580 should in theory be much superior to the GeForce GT 420 in general. (explain)

GeForce GTX 580		192384 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 163584 (568%)

Texel Rate

The GeForce GTX 580 should be quite a bit (more or less 782%) more effective at AF than the GeForce GT 420. (explain)

GeForce GTX 580		49408 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 43808 (782%)

Pixel Rate

If running with a high resolution is important to you, then the GeForce GTX 580 is the winner, by a large margin. (explain)

GeForce GTX 580		37056 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 34256 (1223%)

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 megabytes per second) that can be moved past the external memory interface in one second. It's worked out by multiplying the bus width by the speed of its memory. If the card has DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total number of texture units of the card 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 applied in one second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly record to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.