Radeon HD 4770 vs Radeon HD 6770 1GB

Intro

Compare all that to the Radeon HD 6770 1GB, which comes with a GPU core clock speed of 900 MHz, and 1024 MB of GDDR5 memory running at 1050 MHz through a 128-bit bus. It also features 800 Stream Processors, 40 TAUs, 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 6770 1GB		108 Watts
	Difference: 28 Watts (35%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6770 1GB will be 31% quicker than the Radeon HD 4770 in general, because of its higher bandwidth. (explain)

Radeon HD 6770 1GB		67200 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 16000 (31%)

Texel Rate

The Radeon HD 6770 1GB is a lot (more or less 50%) more effective at AF than the Radeon HD 4770. (explain)

Radeon HD 6770 1GB		36000 Mtexels/sec
Radeon HD 4770		24000 Mtexels/sec
	Difference: 12000 (50%)

Pixel Rate

The Radeon HD 6770 1GB should be just a bit (more or less 20%) faster with regards to FSAA than the Radeon HD 4770, and will be able to handle higher resolutions better. (explain)

Radeon HD 6770 1GB		14400 Mpixels/sec
Radeon HD 4770		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: Memory bandwidth is the largest amount of data (measured in MB per second) that can be moved past the external memory interface in one second. The number is worked out by multiplying the interface width by its memory clock speed. If the card has DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This number is calculated 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 graphics card will be at 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 could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill 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 max fill rate.