Radeon HD 3870 512MB vs Radeon HD 7870

Intro

Compare those specs to the Radeon HD 7870, which has core speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 memory. It features 1280 SPUs as well as 80 Texture Address Units and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 512MB		106 Watts
Radeon HD 7870		175 Watts
	Difference: 69 Watts (65%)

Memory Bandwidth

Theoretically, the Radeon HD 7870 should perform a lot faster than the Radeon HD 3870 512MB overall. (explain)

Radeon HD 7870		153600 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 96000 (167%)

Texel Rate

The Radeon HD 7870 will be quite a bit (approximately 545%) more effective at AF than the Radeon HD 3870 512MB. (explain)

Radeon HD 7870		80000 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 67600 (545%)

Pixel Rate

The Radeon HD 7870 should be a lot (approximately 158%) better at FSAA than the Radeon HD 3870 512MB, and able to handle higher screen resolutions without losing too much performance. (explain)

Radeon HD 7870		32000 Mpixels/sec
Radeon HD 3870 512MB		12400 Mpixels/sec
	Difference: 19600 (158%)

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 (counted in MB per second) that can be transferred across the external memory interface in a second. It is calculated by multiplying the bus width by its memory speed. In the case of DDR memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better 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 are processed per second. This figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

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