Radeon HD 4670 512MB vs Radeon HD 7770

Intro

Compare those specifications to the Radeon HD 7770, which has GPU core speed of 1000 MHz, and 1024 MB of GDDR5 memory set to run at 1125 MHz through a 128-bit bus. It also is made up of 640 Stream Processors, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4670 512MB		70 Watts
Radeon HD 7770		80 Watts
	Difference: 10 Watts (14%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7770 should perform quite a bit faster than the Radeon HD 4670 512MB in general. (explain)

Radeon HD 7770		72000 MB/sec
Radeon HD 4670 512MB		32000 MB/sec
	Difference: 40000 (125%)

Texel Rate

The Radeon HD 7770 is quite a bit (more or less 67%) more effective at texture filtering than the Radeon HD 4670 512MB. (explain)

Radeon HD 7770		40000 Mtexels/sec
Radeon HD 4670 512MB		24000 Mtexels/sec
	Difference: 16000 (67%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 7770 is a better choice, by far. (explain)

Radeon HD 7770		16000 Mpixels/sec
Radeon HD 4670 512MB		6000 Mpixels/sec
	Difference: 10000 (167%)

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 (counted in MB per second) that can be moved past the external memory interface in a second. It is calculated by multiplying the card's interface width by its memory speed. In the case of DDR RAM, it must 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 AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly record to its 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 clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.