GeForce GT 315 vs GeForce GT 420

Intro

Compare all that to the GeForce GT 420, which features a GPU core clock speed of 700 MHz, and 2048 MB of GDDR3 memory running at 900 MHz through a 128-bit bus. It also features 48 Stream Processors, 8 TAUs, 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

Theoretically, the GeForce GT 420 should be a small bit faster than the GeForce GT 315 in general. (explain)

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

Texel Rate

The GeForce GT 315 will be quite a bit (approximately 79%) faster with regards to AF 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 resolution is important to you, then the GeForce GT 315 is a better choice, and very much so. (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 largest amount of information (in units of MB per second) that can be moved over the external memory interface within a second. It is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.