Radeon HD 3870 1GB vs Radeon HD 5770

Intro

Compare those specs to the Radeon HD 5770, which comes with core speeds of 850 MHz on the GPU, and 1200 MHz on the 1024 MB of GDDR5 memory. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 1GB		106 Watts
Radeon HD 5770		108 Watts
	Difference: 2 Watts (2%)

Memory Bandwidth

The Radeon HD 5770 should theoretically be a bit faster than the Radeon HD 3870 1GB overall. (explain)

Radeon HD 5770		76800 MB/sec
Radeon HD 3870 1GB		72000 MB/sec
	Difference: 4800 (7%)

Texel Rate

The Radeon HD 5770 is a lot (approximately 174%) more effective at AF than the Radeon HD 3870 1GB. (explain)

Radeon HD 5770		34000 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 21600 (174%)

Pixel Rate

The Radeon HD 5770 should be just a bit (approximately 10%) more effective at full screen anti-aliasing than the Radeon HD 3870 1GB, and also will be able to handle higher screen resolutions without slowing down too much. (explain)

Radeon HD 5770		13600 Mpixels/sec
Radeon HD 3870 1GB		12400 Mpixels/sec
	Difference: 1200 (10%)

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 (counted in megabytes per second) that can be moved across the external memory interface in one second. The number is worked out by multiplying the bus width by the speed of its memory. If the card has DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range 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 amount of texture units by the core speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the card's 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 output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.