Radeon HD 4850 512MB vs Radeon HD 6770

Intro

Compare those specs to the Radeon HD 6770, which comes with a core clock frequency of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also features a 128-bit bus, and uses a 40 nm design. It is comprised of 800 SPUs, 40 Texture Address Units, 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 4850 512MB		110 Watts
	Difference: 2 Watts (2%)

Memory Bandwidth

Performance-wise, the Radeon HD 6770 should theoretically be a small bit superior to the Radeon HD 4850 512MB in general. (explain)

Radeon HD 6770		67200 MB/sec
Radeon HD 4850 512MB		63552 MB/sec
	Difference: 3648 (6%)

Texel Rate

The Radeon HD 6770 will be a lot (more or less 44%) more effective at anisotropic filtering than the Radeon HD 4850 512MB. (explain)

Radeon HD 6770		36000 Mtexels/sec
Radeon HD 4850 512MB		25000 Mtexels/sec
	Difference: 11000 (44%)

Pixel Rate

The Radeon HD 6770 is a lot (approximately 44%) more effective at FSAA than the Radeon HD 4850 512MB, and should be able to handle higher screen resolutions without losing too much performance. (explain)

Radeon HD 6770		14400 Mpixels/sec
Radeon HD 4850 512MB		10000 Mpixels/sec
	Difference: 4400 (44%)

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 data (measured in megabytes per second) that can be transferred across the external memory interface within a second. It is worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are 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 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 record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka 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 of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.