GeForce GT 420 vs Radeon HD 7950 3GB

Intro

Compare that to the Radeon HD 7950 3GB, which comes with a core clock speed of 800 MHz and a GDDR5 memory frequency of 1250 MHz. It also features a 384-bit memory bus, and uses a 28 nm design. It is comprised of 1792 SPUs, 112 Texture Address Units, and 32 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
Radeon HD 7950 3GB		200 Watts
	Difference: 150 Watts (300%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7950 3GB will be 733% faster than the GeForce GT 420 in general, due to its greater bandwidth. (explain)

Radeon HD 7950 3GB		240000 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 211200 (733%)

Texel Rate

The Radeon HD 7950 3GB should be much (more or less 1500%) faster with regards to anisotropic filtering than the GeForce GT 420. (explain)

Radeon HD 7950 3GB		89600 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 84000 (1500%)

Pixel Rate

The Radeon HD 7950 3GB will be quite a bit (more or less 814%) faster with regards to anti-aliasing than the GeForce GT 420, and also capable of handling higher resolutions better. (explain)

Radeon HD 7950 3GB		25600 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 22800 (814%)

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 maximum amount of data (measured in MB per second) that can be transferred over the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory speed. If it uses DDR type RAM, it should be multiplied by 2 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 high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The higher this number, the better the video 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 maximum number of pixels that the graphics chip could possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel 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 max fill rate.