GeForce GT 315 vs GeForce GT 420

Intro

Compare those specifications to the GeForce GT 420, which features a clock speed of 700 MHz and a GDDR3 memory frequency of 900 MHz. It also features a 128-bit memory bus, and uses a 40 nm design. It is made up of 48 SPUs, 8 Texture Address Units, and 4 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
GeForce GT 315		52 Watts
	Difference: 2 Watts (4%)

Memory Bandwidth

As far as performance goes, the GeForce GT 420 should theoretically be a bit superior to the GeForce GT 315 overall. (explain)

GeForce GT 420		28800 MB/sec
GeForce GT 315		25280 MB/sec
	Difference: 3520 (14%)

Texel Rate

The GeForce GT 315 should be quite a bit (more or less 79%) better at anisotropic filtering than the GeForce GT 420. (explain)

GeForce GT 315		10000 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 4400 (79%)

Pixel Rate

If using a high screen resolution is important to you, then the GeForce GT 315 is the winner, by a large margin. (explain)

GeForce GT 315		5000 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 2200 (79%)

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 information (in units of megabytes per second) that can be transferred across the external memory interface in a second. The number is calculated by multiplying the bus width by the speed of its memory. If it uses DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

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