GeForce GT 315 vs GeForce GT 420

Intro

Compare all that to the GeForce GT 420, which makes use of a 40 nm design. nVidia has set the core speed at 700 MHz. The GDDR3 RAM runs at a frequency of 900 MHz on this particular model. It features 48 SPUs as well as 8 Texture Address Units and 4 Rasterization Operator 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 speaking, the GeForce GT 420 should perform a small bit faster than 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 will be quite a bit (approximately 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

The GeForce GT 315 should be a lot (about 79%) faster with regards to anti-aliasing than the GeForce GT 420, and will be capable of handling higher resolutions without losing too much performance. (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: Bandwidth is the max amount of data (in units of megabytes per second) that can be moved past the external memory interface within a second. The number is calculated by multiplying the card's interface width by its memory speed. If the card has DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This number is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video 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 that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out 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 rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.