Radeon HD 4830 512MB vs Radeon HD 6770 1GB

Intro

Compare those specifications to the Radeon HD 6770 1GB, which comes with core speeds of 900 MHz on the GPU, and 1050 MHz on the 1024 MB of GDDR5 RAM. It features 800 SPUs along with 40 Texture Address Units and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 512MB		95 Watts
Radeon HD 6770 1GB		108 Watts
	Difference: 13 Watts (14%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6770 1GB should be a bit faster than the Radeon HD 4830 512MB overall. (explain)

Radeon HD 6770 1GB		67200 MB/sec
Radeon HD 4830 512MB		57600 MB/sec
	Difference: 9600 (17%)

Texel Rate

The Radeon HD 6770 1GB should be quite a bit (about 96%) more effective at AF than the Radeon HD 4830 512MB. (explain)

Radeon HD 6770 1GB		36000 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 17600 (96%)

Pixel Rate

The Radeon HD 6770 1GB should be quite a bit (approximately 57%) better at AA than the Radeon HD 4830 512MB, and also will be able to handle higher screen resolutions better. (explain)

Radeon HD 6770 1GB		14400 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 5200 (57%)

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 information (in units of megabytes per second) that can be transported over the external memory interface in one second. It is calculated by multiplying the bus width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This number is calculated by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the graphics 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 amount of pixels that the graphics chip could possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.