GeForce GT 420 vs Radeon HD 4770

Intro

Compare all that to the Radeon HD 4770, which has a clock frequency of 750 MHz and a GDDR5 memory speed of 800 MHz. It also features a 128-bit bus, and uses a 40 nm design. It is comprised of 640(128x5) SPUs, 32 Texture Address Units, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
Radeon HD 4770		80 Watts
	Difference: 30 Watts (60%)

Memory Bandwidth

The Radeon HD 4770 should in theory be quite a bit faster than the GeForce GT 420 overall. (explain)

Radeon HD 4770		51200 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 22400 (78%)

Texel Rate

The Radeon HD 4770 will be a lot (about 329%) more effective at anisotropic filtering than the GeForce GT 420. (explain)

Radeon HD 4770		24000 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 18400 (329%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 4770 is superior to the GeForce GT 420, by far. (explain)

Radeon HD 4770		12000 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 9200 (329%)

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 data (measured in MB per second) that can be transported across the external memory interface in a second. It is worked out by multiplying the bus width by its memory speed. If the card has DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This is calculated by multiplying the total amount of texture units of the card 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 per second.

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