Radeon HD 5770 vs Radeon HD 7770

Intro

Compare that to the Radeon HD 7770, which comes with a clock speed of 1000 MHz and a GDDR5 memory speed of 1125 MHz. It also features a 128-bit bus, and makes use of a 28 nm design. It is comprised 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 5770		108 Watts
	Difference: 28 Watts (35%)

Memory Bandwidth

Theoretically, the Radeon HD 5770 should be a bit faster than the Radeon HD 7770 in general. (explain)

Radeon HD 5770		76800 MB/sec
Radeon HD 7770		72000 MB/sec
	Difference: 4800 (7%)

Texel Rate

The Radeon HD 7770 will be just a bit (about 18%) more effective at AF than the Radeon HD 5770. (explain)

Radeon HD 7770		40000 Mtexels/sec
Radeon HD 5770		34000 Mtexels/sec
	Difference: 6000 (18%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 7770 is superior to the Radeon HD 5770, though only just barely. (explain)

Radeon HD 7770		16000 Mpixels/sec
Radeon HD 5770		13600 Mpixels/sec
	Difference: 2400 (18%)

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 largest amount of information (measured in MB per second) that can be transported across the external memory interface in a second. The number is calculated by multiplying the bus width by its memory speed. If the card has DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the 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 texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also 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, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.