Radeon HD 4830 1GB vs Radeon HD 4850 1GB

Intro

Compare those specs to the Radeon HD 4850 1GB, which features clock speeds of 625 MHz on the GPU, and 993 MHz on the 1024 MB of GDDR4 memory. It features 800(160x5) 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 1GB		95 Watts
Radeon HD 4850 1GB		110 Watts
	Difference: 15 Watts (16%)

Memory Bandwidth

In theory, the Radeon HD 4850 1GB should be a small bit faster than the Radeon HD 4830 1GB overall. (explain)

Radeon HD 4850 1GB		63552 MB/sec
Radeon HD 4830 1GB		57600 MB/sec
	Difference: 5952 (10%)

Texel Rate

The Radeon HD 4850 1GB is much (approximately 36%) faster with regards to AF than the Radeon HD 4830 1GB. (explain)

Radeon HD 4850 1GB		25000 Mtexels/sec
Radeon HD 4830 1GB		18400 Mtexels/sec
	Difference: 6600 (36%)

Pixel Rate

The Radeon HD 4850 1GB should be a bit (more or less 9%) more effective at AA than the Radeon HD 4830 1GB, and also should be capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 4850 1GB		10000 Mpixels/sec
Radeon HD 4830 1GB		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 max amount of information (counted in megabytes per second) that can be transferred over the external memory interface in one second. It's calculated by multiplying the card's bus width by the speed of its memory. If it uses DDR type RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's 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 amount of texture map elements (texels) that are processed in one second. This is worked out by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.