Radeon HD 3850 256MB vs Radeon HD 4830 512MB

Intro

Compare that to the Radeon HD 4830 512MB, which comes with a clock frequency of 575 MHz and a GDDR3 memory speed of 900 MHz. It also uses a 256-bit bus, and uses a 55 nm design. It is made up of 640(128x5) SPUs, 32 TAUs, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3850 256MB		75 Watts
Radeon HD 4830 512MB		95 Watts
	Difference: 20 Watts (27%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4830 512MB should be 9% faster than the Radeon HD 3850 256MB in general, because of its greater data rate. (explain)

Radeon HD 4830 512MB		57600 MB/sec
Radeon HD 3850 256MB		52992 MB/sec
	Difference: 4608 (9%)

Texel Rate

The Radeon HD 4830 512MB will be a lot (approximately 72%) faster with regards to texture filtering than the Radeon HD 3850 256MB. (explain)

Radeon HD 4830 512MB		18400 Mtexels/sec
Radeon HD 3850 256MB		10688 Mtexels/sec
	Difference: 7712 (72%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 3850 256MB is a better choice, but only just. (explain)

Radeon HD 3850 256MB		10688 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 1488 (16%)

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 max amount of information (counted in MB per second) that can be transferred across the external memory interface within a second. The number is calculated by multiplying the bus width by the speed of its memory. If the card has DDR RAM, it should 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 anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units 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 rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.