Radeon HD 4850 2GB vs Radeon HD 6770 1GB

Intro

Compare all that to the Radeon HD 6770 1GB, which comes with a core clock frequency of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also makes use of a 128-bit bus, and makes use of a 40 nm design. It is comprised of 800 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6770 1GB		108 Watts
Radeon HD 4850 2GB		110 Watts
	Difference: 2 Watts (2%)

Memory Bandwidth

Theoretically, the Radeon HD 6770 1GB should perform just a bit faster than the Radeon HD 4850 2GB overall. (explain)

Radeon HD 6770 1GB		67200 MB/sec
Radeon HD 4850 2GB		63552 MB/sec
	Difference: 3648 (6%)

Texel Rate

The Radeon HD 6770 1GB will be quite a bit (about 44%) faster with regards to anisotropic filtering than the Radeon HD 4850 2GB. (explain)

Radeon HD 6770 1GB		36000 Mtexels/sec
Radeon HD 4850 2GB		25000 Mtexels/sec
	Difference: 11000 (44%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 6770 1GB is superior to the Radeon HD 4850 2GB, and very much so. (explain)

Radeon HD 6770 1GB		14400 Mpixels/sec
Radeon HD 4850 2GB		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 data (in units of megabytes per second) that can be transferred across the external memory interface within a second. The number is worked out by multiplying the interface width by its memory speed. If it uses DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the most pixels the video card can possibly write to the 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 card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.