GeForce GT 420 vs Radeon HD 4670 512MB

Intro

Compare that to the Radeon HD 4670 512MB, which comes with GPU clock speed of 750 MHz, and 512 MB of GDDR4/GDDR3/DDR3/DDR2 memory running at 1000 MHz through a 128-bit bus. It also is comprised of 320(64x5) Stream Processors, 32 TAUs, and 8 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
Radeon HD 4670 512MB		70 Watts
	Difference: 20 Watts (40%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4670 512MB should be a little bit faster than the GeForce GT 420 in general. (explain)

Radeon HD 4670 512MB		32000 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 3200 (11%)

Texel Rate

The Radeon HD 4670 512MB is quite a bit (about 329%) faster with regards to AF than the GeForce GT 420. (explain)

Radeon HD 4670 512MB		24000 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 18400 (329%)

Pixel Rate

The Radeon HD 4670 512MB is a lot (more or less 114%) better at full screen anti-aliasing than the GeForce GT 420, and will be able to handle higher resolutions more effectively. (explain)

Radeon HD 4670 512MB		6000 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 3200 (114%)

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 data (in units of MB per second) that can be transferred across the external memory interface within a second. The number is calculated by multiplying the interface width by its memory speed. In the case of DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number 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 outputting the pixels (image) to the screen. The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.