Radeon HD 3850 256MB vs Radeon HD 6790

Intro

Compare those specs to the Radeon HD 6790, which makes use of a 40 nm design. AMD has set the core frequency at 840 MHz. The GDDR5 RAM is set to run at a speed of 1050 MHz on this card. It features 800 SPUs along with 40 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3850 256MB		75 Watts
Radeon HD 6790		150 Watts
	Difference: 75 Watts (100%)

Memory Bandwidth

Theoretically, the Radeon HD 6790 should perform quite a bit faster than the Radeon HD 3850 256MB overall. (explain)

Radeon HD 6790		134400 MB/sec
Radeon HD 3850 256MB		52992 MB/sec
	Difference: 81408 (154%)

Texel Rate

The Radeon HD 6790 should be quite a bit (about 214%) better at anisotropic filtering than the Radeon HD 3850 256MB. (explain)

Radeon HD 6790		33600 Mtexels/sec
Radeon HD 3850 256MB		10688 Mtexels/sec
	Difference: 22912 (214%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon HD 6790 is superior to the Radeon HD 3850 256MB, and very much so. (explain)

Radeon HD 6790		13440 Mpixels/sec
Radeon HD 3850 256MB		10688 Mpixels/sec
	Difference: 2752 (26%)

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 (in units of megabytes per second) that can be transferred over the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory speed. If it uses DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.