Radeon HD 4870 512MB vs Radeon HD 6770

Intro

Compare those specs to the Radeon HD 6770, which features a clock frequency of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also uses a 128-bit memory bus, and makes use of a 40 nm design. It is made up of 800 SPUs, 40 TAUs, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6770		108 Watts
Radeon HD 4870 512MB		150 Watts
	Difference: 42 Watts (39%)

Memory Bandwidth

The Radeon HD 4870 512MB should in theory be much faster than the Radeon HD 6770 in general. (explain)

Radeon HD 4870 512MB		115200 MB/sec
Radeon HD 6770		67200 MB/sec
	Difference: 48000 (71%)

Texel Rate

The Radeon HD 6770 will be just a bit (more or less 20%) more effective at AF than the Radeon HD 4870 512MB. (explain)

Radeon HD 6770		36000 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 6000 (20%)

Pixel Rate

The Radeon HD 6770 will be just a bit (about 20%) faster with regards to AA than the Radeon HD 4870 512MB, and able to handle higher screen resolutions more effectively. (explain)

Radeon HD 6770		14400 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 2400 (20%)

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 max amount of data (measured in MB per second) that can be moved over the external memory interface within a second. It is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the 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 texture map elements (texels) that can be applied per second. This number is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output 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 potential to reach the maximum fill rate.