Radeon HD 3870 512MB vs Radeon HD 7770

Intro

Compare those specs to the Radeon HD 7770, which has a GPU core clock speed of 1000 MHz, and 1024 MB of GDDR5 memory running at 1125 MHz through a 128-bit bus. It also is made up of 640 Stream Processors, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7770		80 Watts
Radeon HD 3870 512MB		106 Watts
	Difference: 26 Watts (33%)

Memory Bandwidth

As far as performance goes, the Radeon HD 7770 should theoretically be a lot better than the Radeon HD 3870 512MB in general. (explain)

Radeon HD 7770		72000 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 14400 (25%)

Texel Rate

The Radeon HD 7770 is much (about 223%) faster with regards to AF than the Radeon HD 3870 512MB. (explain)

Radeon HD 7770		40000 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 27600 (223%)

Pixel Rate

The Radeon HD 7770 will be quite a bit (approximately 29%) better at full screen anti-aliasing than the Radeon HD 3870 512MB, and also should be able to handle higher screen resolutions while still performing well. (explain)

Radeon HD 7770		16000 Mpixels/sec
Radeon HD 3870 512MB		12400 Mpixels/sec
	Difference: 3600 (29%)

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 max amount of information (measured in MB per second) that can be transferred past the external memory interface in a second. It's worked out by multiplying the card's interface width by its memory speed. In the case of DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better 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 can be processed per second. This figure is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the 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 most pixels that the graphics chip can possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.