Radeon HD 4770 vs Radeon HD 5770

Intro

Compare all of that to the Radeon HD 5770, which comes with GPU clock speed of 850 MHz, and 1024 MB of GDDR5 memory set to run at 1200 MHz through a 128-bit bus. It also is made up of 800(160x5) Stream Processors, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4770		80 Watts
Radeon HD 5770		108 Watts
	Difference: 28 Watts (35%)

Memory Bandwidth

The Radeon HD 5770 should theoretically perform quite a bit faster than the Radeon HD 4770 in general. (explain)

Radeon HD 5770		76800 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 25600 (50%)

Texel Rate

The Radeon HD 5770 should be a lot (about 42%) more effective at anisotropic filtering than the Radeon HD 4770. (explain)

Radeon HD 5770		34000 Mtexels/sec
Radeon HD 4770		24000 Mtexels/sec
	Difference: 10000 (42%)

Pixel Rate

The Radeon HD 5770 should be just a bit (about 13%) better at anti-aliasing than the Radeon HD 4770, and capable of handling higher screen resolutions without slowing down too much. (explain)

Radeon HD 5770		13600 Mpixels/sec
Radeon HD 4770		12000 Mpixels/sec
	Difference: 1600 (13%)

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 maximum amount of data (measured in megabytes per second) that can be moved over the external memory interface in one second. It is calculated by multiplying the bus width by its memory clock speed. In the case of DDR memory, it 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 processed per second. This is calculated 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 one second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.