GeForce GT 240 GDDR5 1GB vs GeForce GT 420

Intro

Compare all of that to the GeForce GT 420, which uses a 40 nm design. nVidia has set the core speed at 700 MHz. The GDDR3 RAM works at a speed of 900 MHz on this specific model. It features 48 SPUs as well as 8 TAUs and 4 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
GeForce GT 240 GDDR5 1GB		70 Watts
	Difference: 20 Watts (40%)

Memory Bandwidth

Theoretically speaking, the GeForce GT 240 GDDR5 1GB should be 89% quicker than the GeForce GT 420 overall, due to its greater bandwidth. (explain)

GeForce GT 240 GDDR5 1GB		54400 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 25600 (89%)

Texel Rate

The GeForce GT 240 GDDR5 1GB is a lot (about 214%) better at texture filtering than the GeForce GT 420. (explain)

GeForce GT 240 GDDR5 1GB		17600 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 12000 (214%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the GeForce GT 240 GDDR5 1GB is superior to the GeForce GT 420, by a large margin. (explain)

GeForce GT 240 GDDR5 1GB		4400 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 1600 (57%)

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 maximum amount of data (counted in MB per second) that can be transported past the external memory interface in a second. The number is worked out by multiplying the bus width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better 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 per second. This figure is calculated by multiplying the total number of texture units by the core speed of the chip. The higher the texel rate, the better the graphics 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 that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.