Radeon HD 3850 256MB vs Radeon HD 6870

Intro

Compare those specifications to the Radeon HD 6870, which features a clock frequency of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also uses a 256-bit bus, and uses a 40 nm design. It is comprised of 1120 SPUs, 56 Texture Address Units, and 32 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 6870		151 Watts
	Difference: 76 Watts (101%)

Memory Bandwidth

Performance-wise, the Radeon HD 6870 should in theory be much better than the Radeon HD 3850 256MB overall. (explain)

Radeon HD 6870		134400 MB/sec
Radeon HD 3850 256MB		52992 MB/sec
	Difference: 81408 (154%)

Texel Rate

The Radeon HD 6870 is much (about 372%) faster with regards to anisotropic filtering than the Radeon HD 3850 256MB. (explain)

Radeon HD 6870		50400 Mtexels/sec
Radeon HD 3850 256MB		10688 Mtexels/sec
	Difference: 39712 (372%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon HD 6870 is a better choice, and very much so. (explain)

Radeon HD 6870		28800 Mpixels/sec
Radeon HD 3850 256MB		10688 Mpixels/sec
	Difference: 18112 (169%)

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 largest amount of data (measured in MB per second) that can be transported over the external memory interface in a second. It's calculated by multiplying the interface width by the speed of its memory. If the card has DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.