Radeon HD 3870 1GB vs Radeon HD 7870

Intro

Compare those specs to the Radeon HD 7870, which comes with a GPU core clock speed of 1000 MHz, and 2048 MB of GDDR5 memory set to run at 1200 MHz through a 256-bit bus. It also is made up of 1280 SPUs, 80 TAUs, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 1GB		106 Watts
Radeon HD 7870		175 Watts
	Difference: 69 Watts (65%)

Memory Bandwidth

Performance-wise, the Radeon HD 7870 should theoretically be quite a bit superior to the Radeon HD 3870 1GB overall. (explain)

Radeon HD 7870		153600 MB/sec
Radeon HD 3870 1GB		72000 MB/sec
	Difference: 81600 (113%)

Texel Rate

The Radeon HD 7870 should be much (more or less 545%) faster with regards to AF than the Radeon HD 3870 1GB. (explain)

Radeon HD 7870		80000 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 67600 (545%)

Pixel Rate

The Radeon HD 7870 will be quite a bit (about 158%) more effective at full screen anti-aliasing than the Radeon HD 3870 1GB, and should be able to handle higher screen resolutions while still performing well. (explain)

Radeon HD 7870		32000 Mpixels/sec
Radeon HD 3870 1GB		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: Memory bandwidth is the largest amount of information (in units of MB per second) that can be transported over the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total texture units 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 applied in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of 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 fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.