Radeon HD 6670 (OEM) 1GB vs Radeon HD 7990

Intro

Compare all that to the Radeon HD 7990, which features core clock speeds of 950 MHz on the GPU, and 1500 MHz on the 3072 MB of GDDR5 RAM. It features 2048 SPUs along with 128 Texture Address Units and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6670 (OEM) 1GB		63 Watts
Radeon HD 7990		375 Watts
	Difference: 312 Watts (495%)

Memory Bandwidth

Performance-wise, the Radeon HD 7990 should theoretically be a lot better than the Radeon HD 6670 (OEM) 1GB in general. (explain)

Radeon HD 7990		576000 MB/sec
Radeon HD 6670 (OEM) 1GB		64000 MB/sec
	Difference: 512000 (800%)

Texel Rate

The Radeon HD 7990 is quite a bit (about 1167%) more effective at AF than the Radeon HD 6670 (OEM) 1GB. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon HD 6670 (OEM) 1GB		19200 Mtexels/sec
	Difference: 224000 (1167%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon HD 7990 is the winner, by a large margin. (explain)

Radeon HD 7990		60800 Mpixels/sec
Radeon HD 6670 (OEM) 1GB		6400 Mpixels/sec
	Difference: 54400 (850%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the maximum amount of information (in units of megabytes per second) that can be transported across the external memory interface within a second. It is worked out by multiplying the card's interface width by its memory speed. In the case of DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total texture units by the core speed of the chip. The better this number, the better the graphics 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 maximum amount of pixels the video card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.