Radeon HD 4850 1GB vs Radeon HD 6770

Intro

Compare all that to the Radeon HD 6770, which has a core clock speed of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also features a 128-bit memory bus, and makes use of 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 1GB		110 Watts
	Difference: 2 Watts (2%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6770 should in theory be just a bit better than the Radeon HD 4850 1GB in general. (explain)

Radeon HD 6770		67200 MB/sec
Radeon HD 4850 1GB		63552 MB/sec
	Difference: 3648 (6%)

Texel Rate

The Radeon HD 6770 should be a lot (approximately 44%) better at texture filtering than the Radeon HD 4850 1GB. (explain)

Radeon HD 6770		36000 Mtexels/sec
Radeon HD 4850 1GB		25000 Mtexels/sec
	Difference: 11000 (44%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon HD 6770 is the winner, and very much so. (explain)

Radeon HD 6770		14400 Mpixels/sec
Radeon HD 4850 1GB		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: Bandwidth is the largest amount of information (counted in MB per second) that can be transported past the external memory interface within a second. The number is calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher 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 are processed per second. This is calculated by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the graphics 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 most pixels that the graphics chip could possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.