Radeon HD 4890 1GB vs Radeon HD 6770

Intro

Compare all of that to the Radeon HD 6770, which has core speeds of 900 MHz on the GPU, and 1050 MHz on the 512 MB of GDDR5 memory. It features 800 SPUs as well as 40 Texture Address Units and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6770		108 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 82 Watts (76%)

Memory Bandwidth

Theoretically, the Radeon HD 4890 1GB should perform a lot faster than the Radeon HD 6770 in general. (explain)

Radeon HD 4890 1GB		124800 MB/sec
Radeon HD 6770		67200 MB/sec
	Difference: 57600 (86%)

Texel Rate

The Radeon HD 4890 1GB is a little bit (about 11%) faster with regards to anisotropic filtering than the Radeon HD 6770. (explain)

Radeon HD 4890 1GB		40000 Mtexels/sec
Radeon HD 6770		36000 Mtexels/sec
	Difference: 4000 (11%)

Pixel Rate

The Radeon HD 4890 1GB will be just a bit (more or less 11%) faster with regards to anti-aliasing than the Radeon HD 6770, and should be capable of handling higher resolutions better. (explain)

Radeon HD 4890 1GB		16000 Mpixels/sec
Radeon HD 6770		14400 Mpixels/sec
	Difference: 1600 (11%)

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 information (in units of MB per second) that can be transported past the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total number of texture units by the core speed of the chip. The higher this number, 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 most pixels that the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. 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 rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.