GeForce GT 240 GDDR5 1GB vs GeForce GT 420

Intro

Compare all that to the GeForce GT 420, which features GPU 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 Texture Address Units, and 4 ROPs.

Display Graphs

Hide Graphs

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, the GeForce GT 240 GDDR5 1GB should be much faster than the GeForce GT 420 overall. (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 should be much (approximately 214%) more effective at anisotropic 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

The GeForce GT 240 GDDR5 1GB should be a lot (more or less 57%) better at full screen anti-aliasing than the GeForce GT 420, and also should be capable of handling higher screen resolutions while still performing well. (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 (in units of megabytes per second) that can be transferred across the external memory interface in one second. The number is worked out by multiplying the card's bus width by the speed of its memory. In the case of DDR memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's 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 number of texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly record to its local memory in a 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 outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.