GeForce GT 240 GDDR5 1GB vs Radeon HD 4830 1GB

Intro

Compare those specifications to the Radeon HD 4830 1GB, which has a core clock speed of 575 MHz and a GDDR4 memory speed of 900 MHz. It also features a 256-bit bus, and makes use of a 55 nm design. It features 640(128x5) SPUs, 32 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 240 GDDR5 1GB		70 Watts
Radeon HD 4830 1GB		95 Watts
	Difference: 25 Watts (36%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4830 1GB should perform just a bit faster than the GeForce GT 240 GDDR5 1GB overall. (explain)

Radeon HD 4830 1GB		57600 MB/sec
GeForce GT 240 GDDR5 1GB		54400 MB/sec
	Difference: 3200 (6%)

Texel Rate

The Radeon HD 4830 1GB will be just a bit (more or less 5%) more effective at AF than the GeForce GT 240 GDDR5 1GB. (explain)

Radeon HD 4830 1GB		18400 Mtexels/sec
GeForce GT 240 GDDR5 1GB		17600 Mtexels/sec
	Difference: 800 (5%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon HD 4830 1GB is the winner, and very much so. (explain)

Radeon HD 4830 1GB		9200 Mpixels/sec
GeForce GT 240 GDDR5 1GB		4400 Mpixels/sec
	Difference: 4800 (109%)

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 data (counted in MB per second) that can be moved over the external memory interface in one second. It is calculated by multiplying the card's bus width by its memory clock speed. If it uses DDR memory, the result should be multiplied by 2 once again. If 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 high resolutions.

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

Pixel Rate: Pixel rate is the most 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 worked out by multiplying the number of colour ROPs by the clock 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 quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.