Radeon HD 4890 2GB vs Radeon HD 6670 (OEM) 1GB

Intro

Compare that to the Radeon HD 6670 (OEM) 1GB, which comes with core speeds of 800 MHz on the GPU, and 1000 MHz on the 1024 MB of GDDR5 memory. It features 480 SPUs along with 24 Texture Address Units and 8 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6670 (OEM) 1GB		63 Watts
Radeon HD 4890 2GB		190 Watts
	Difference: 127 Watts (202%)

Memory Bandwidth

The Radeon HD 4890 2GB should in theory be quite a bit faster than the Radeon HD 6670 (OEM) 1GB in general. (explain)

Radeon HD 4890 2GB		124800 MB/sec
Radeon HD 6670 (OEM) 1GB		64000 MB/sec
	Difference: 60800 (95%)

Texel Rate

The Radeon HD 4890 2GB is quite a bit (about 108%) more effective at texture filtering than the Radeon HD 6670 (OEM) 1GB. (explain)

Radeon HD 4890 2GB		40000 Mtexels/sec
Radeon HD 6670 (OEM) 1GB		19200 Mtexels/sec
	Difference: 20800 (108%)

Pixel Rate

The Radeon HD 4890 2GB should be quite a bit (approximately 150%) faster with regards to full screen anti-aliasing than the Radeon HD 6670 (OEM) 1GB, and should be capable of handling higher screen resolutions better. (explain)

Radeon HD 4890 2GB		16000 Mpixels/sec
Radeon HD 6670 (OEM) 1GB		6400 Mpixels/sec
	Difference: 9600 (150%)

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 maximum amount of data (in units of MB per second) that can be moved past the external memory interface in one second. It is calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR RAM, it must be multiplied by 2 once 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 anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per 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 this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.