GeForce GT 340 1GB vs GeForce GT 420

Intro

Compare those specifications to the GeForce GT 420, which uses a 40 nm design. nVidia has clocked the core speed at 700 MHz. The GDDR3 memory runs at a speed of 900 MHz on this particular card. It features 48 SPUs as well as 8 Texture Address Units 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 340 1GB		69 Watts
	Difference: 19 Watts (38%)

Memory Bandwidth

In theory, the GeForce GT 340 1GB should be 89% quicker than the GeForce GT 420 overall, because of its greater data rate. (explain)

GeForce GT 340 1GB		54400 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 25600 (89%)

Texel Rate

The GeForce GT 340 1GB is a lot (more or less 214%) better at texture filtering than the GeForce GT 420. (explain)

GeForce GT 340 1GB		17600 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 12000 (214%)

Pixel Rate

If using high levels of AA is important to you, then the GeForce GT 340 1GB is the winner, and very much so. (explain)

GeForce GT 340 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 max amount of information (counted in megabytes per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory clock speed. If the card has DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the 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 amount of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many 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.