GeForce GT 420 vs Radeon HD 4850 2GB

Intro

Compare all that to the Radeon HD 4850 2GB, which uses a 55 nm design. AMD has set the core speed at 625 MHz. The GDDR4 RAM is set to run at a frequency of 993 MHz on this particular model. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
Radeon HD 4850 2GB		110 Watts
	Difference: 60 Watts (120%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4850 2GB should be a lot faster than the GeForce GT 420 in general. (explain)

Radeon HD 4850 2GB		63552 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 34752 (121%)

Texel Rate

The Radeon HD 4850 2GB should be a lot (more or less 346%) faster with regards to anisotropic filtering than the GeForce GT 420. (explain)

Radeon HD 4850 2GB		25000 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 19400 (346%)

Pixel Rate

The Radeon HD 4850 2GB should be a lot (more or less 257%) better at AA than the GeForce GT 420, and also should be capable of handling higher screen resolutions more effectively. (explain)

Radeon HD 4850 2GB		10000 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 7200 (257%)

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 max amount of information (counted in MB per second) that can be transported across the external memory interface within a second. It 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 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.