Radeon HD 3850 512MB vs Radeon HD 4770

Intro

Compare that to the Radeon HD 4770, which uses a 40 nm design. AMD has clocked the core speed at 750 MHz. The GDDR5 RAM is set to run at a frequency of 800 MHz on this specific card. It features 640(128x5) SPUs as well as 32 TAUs and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3850 512MB		75 Watts
Radeon HD 4770		80 Watts
	Difference: 5 Watts (7%)

Memory Bandwidth

The Radeon HD 3850 512MB should theoretically be a small bit faster than the Radeon HD 4770 overall. (explain)

Radeon HD 3850 512MB		52992 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 1792 (4%)

Texel Rate

The Radeon HD 4770 will be a lot (about 125%) better at texture filtering than the Radeon HD 3850 512MB. (explain)

Radeon HD 4770		24000 Mtexels/sec
Radeon HD 3850 512MB		10688 Mtexels/sec
	Difference: 13312 (125%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 4770 is the winner, though only just barely. (explain)

Radeon HD 4770		12000 Mpixels/sec
Radeon HD 3850 512MB		10688 Mpixels/sec
	Difference: 1312 (12%)

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 data (counted in megabytes per second) that can be transferred across the external memory interface within a second. It's worked out by multiplying the interface width by its memory clock speed. In the case of DDR memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This number is calculated by multiplying the total texture units of the card 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 processed per second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.