GeForce GT 420 vs Radeon HD 3870 512MB

Intro

Compare those specifications to the Radeon HD 3870 512MB, which makes use of a 55 nm design. AMD has clocked the core speed at 775 MHz. The GDDR3 memory runs at a speed of 900 MHz on this model. It features 320(64x5) SPUs as well as 16 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
Radeon HD 3870 512MB		106 Watts
	Difference: 56 Watts (112%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 3870 512MB should perform much faster than the GeForce GT 420 in general. (explain)

Radeon HD 3870 512MB		57600 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 28800 (100%)

Texel Rate

The Radeon HD 3870 512MB should be a lot (about 121%) more effective at texture filtering than the GeForce GT 420. (explain)

Radeon HD 3870 512MB		12400 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 6800 (121%)

Pixel Rate

The Radeon HD 3870 512MB should be quite a bit (about 343%) faster with regards to full screen anti-aliasing than the GeForce GT 420, and also will be capable of handling higher screen resolutions without losing too much performance. (explain)

Radeon HD 3870 512MB		12400 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 9600 (343%)

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 moved across the external memory interface within a second. It is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.