Radeon HD 4830 512MB vs Radeon HD 4850 512MB

Intro

Compare that to the Radeon HD 4850 512MB, which makes use of a 55 nm design. AMD has set the core speed at 625 MHz. The GDDR3 RAM works at a speed of 993 MHz on this particular card. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 512MB		95 Watts
Radeon HD 4850 512MB		110 Watts
	Difference: 15 Watts (16%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4850 512MB should perform a bit faster than the Radeon HD 4830 512MB in general. (explain)

Radeon HD 4850 512MB		63552 MB/sec
Radeon HD 4830 512MB		57600 MB/sec
	Difference: 5952 (10%)

Texel Rate

The Radeon HD 4850 512MB is quite a bit (approximately 36%) faster with regards to texture filtering than the Radeon HD 4830 512MB. (explain)

Radeon HD 4850 512MB		25000 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 6600 (36%)

Pixel Rate

The Radeon HD 4850 512MB will be a small bit (about 9%) faster with regards to full screen anti-aliasing than the Radeon HD 4830 512MB, and also capable of handling higher resolutions more effectively. (explain)

Radeon HD 4850 512MB		10000 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 800 (9%)

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 (in units of megabytes per second) that can be moved past the external memory interface within a second. The number is calculated by multiplying the bus width by its memory clock speed. If the card has DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.