Radeon HD 3870 1GB vs Radeon HD 3870 512MB

Intro

Compare those specifications to the Radeon HD 3870 512MB, which features core clock speeds of 775 MHz on the GPU, and 900 MHz on the 512 MB of GDDR3 RAM. It features 320(64x5) SPUs along with 16 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Both cards have the same power consumption.

Memory Bandwidth

As far as performance goes, the Radeon HD 3870 1GB should theoretically be much better than the Radeon HD 3870 512MB overall. (explain)

Radeon HD 3870 1GB		72000 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 14400 (25%)

Texel Rate

Both cards have exactly the same texel fill rate, so in theory they should perform equally good at at AF. (explain)

Pixel Rate

Both cards have the exact same pixel fill rate, so in theory they should be equally good at at full screen anti-aliasing, and be capable of handling the same resolutions. (explain)

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 transported over the external memory interface within a second. It's calculated by multiplying the bus width by the speed of its memory. If the card has DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The number 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 fill 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.