Radeon HD 5870 vs Radeon HD 7770

Intro

Compare that to the Radeon HD 7770, which has GPU clock speed of 1000 MHz, and 1024 MB of GDDR5 RAM running at 1125 MHz through a 128-bit bus. It also is made up of 640 SPUs, 40 TAUs, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7770		80 Watts
Radeon HD 5870		188 Watts
	Difference: 108 Watts (135%)

Memory Bandwidth

In theory, the Radeon HD 5870 should be 113% quicker than the Radeon HD 7770 overall, due to its greater bandwidth. (explain)

Radeon HD 5870		153600 MB/sec
Radeon HD 7770		72000 MB/sec
	Difference: 81600 (113%)

Texel Rate

The Radeon HD 5870 should be quite a bit (about 70%) better at AF than the Radeon HD 7770. (explain)

Radeon HD 5870		68000 Mtexels/sec
Radeon HD 7770		40000 Mtexels/sec
	Difference: 28000 (70%)

Pixel Rate

The Radeon HD 5870 is quite a bit (approximately 70%) faster with regards to FSAA than the Radeon HD 7770, and also able to handle higher screen resolutions while still performing well. (explain)

Radeon HD 5870		27200 Mpixels/sec
Radeon HD 7770		16000 Mpixels/sec
	Difference: 11200 (70%)

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 (in units of MB per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR type RAM, the result should be multiplied by 2 again. If 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, HDR and high resolutions.

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

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