Radeon HD 4830 512MB vs Radeon HD 6750 1GB

Intro

Compare that to the Radeon HD 6750 1GB, which has GPU core speed of 725 MHz, and 1024 MB of GDDR5 memory set to run at 1000 MHz through a 128-bit bus. It also features 720 Stream Processors, 36 TAUs, and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6750 1GB		86 Watts
Radeon HD 4830 512MB		95 Watts
	Difference: 9 Watts (10%)

Memory Bandwidth

Theoretically, the Radeon HD 6750 1GB should be a small bit faster than the Radeon HD 4830 512MB in general. (explain)

Radeon HD 6750 1GB		64000 MB/sec
Radeon HD 4830 512MB		57600 MB/sec
	Difference: 6400 (11%)

Texel Rate

The Radeon HD 6750 1GB will be quite a bit (approximately 42%) more effective at anisotropic filtering than the Radeon HD 4830 512MB. (explain)

Radeon HD 6750 1GB		26100 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 7700 (42%)

Pixel Rate

The Radeon HD 6750 1GB should be much (about 26%) faster with regards to FSAA than the Radeon HD 4830 512MB, and will be able to handle higher resolutions without losing too much performance. (explain)

Radeon HD 6750 1GB		11600 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 2400 (26%)

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 across the external memory interface within a second. It's worked out by multiplying the bus width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This number is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher the texel rate, the better the 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 card could possibly record to its local memory per 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 - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.