Radeon HD 3850 1GB vs Radeon HD 4850 512MB

Intro

Compare all of that to the Radeon HD 4850 512MB, which comes with a core clock speed of 625 MHz and a GDDR3 memory speed of 993 MHz. It also features a 256-bit memory bus, and uses a 55 nm design. It is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3850 1GB		75 Watts
Radeon HD 4850 512MB		110 Watts
	Difference: 35 Watts (47%)

Memory Bandwidth

Theoretically, the Radeon HD 4850 512MB should perform a little bit faster than the Radeon HD 3850 1GB overall. (explain)

Radeon HD 4850 512MB		63552 MB/sec
Radeon HD 3850 1GB		52992 MB/sec
	Difference: 10560 (20%)

Texel Rate

The Radeon HD 4850 512MB will be a lot (more or less 134%) better at AF than the Radeon HD 3850 1GB. (explain)

Radeon HD 4850 512MB		25000 Mtexels/sec
Radeon HD 3850 1GB		10688 Mtexels/sec
	Difference: 14312 (134%)

Pixel Rate

The Radeon HD 3850 1GB is a bit (approximately 7%) more effective at full screen anti-aliasing than the Radeon HD 4850 512MB, and should be able to handle higher resolutions more effectively. (explain)

Radeon HD 3850 1GB		10688 Mpixels/sec
Radeon HD 4850 512MB		10000 Mpixels/sec
	Difference: 688 (7%)

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 (counted in MB per second) that can be transferred over the external memory interface in a second. It's worked out by multiplying the card's bus width by its memory speed. If it uses DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better 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 texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one 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 colour ROPs by the the core speed of the card. 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 many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.