Radeon HD 4670 512MB vs Radeon HD 6770 1GB

Intro

Compare those specifications to the Radeon HD 6770 1GB, which uses a 40 nm design. AMD has set the core speed at 900 MHz. The GDDR5 memory runs at a frequency of 1050 MHz on this card. It features 800 SPUs along with 40 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4670 512MB		70 Watts
Radeon HD 6770 1GB		108 Watts
	Difference: 38 Watts (54%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6770 1GB should in theory be quite a bit superior to the Radeon HD 4670 512MB overall. (explain)

Radeon HD 6770 1GB		67200 MB/sec
Radeon HD 4670 512MB		32000 MB/sec
	Difference: 35200 (110%)

Texel Rate

The Radeon HD 6770 1GB is a lot (about 50%) better at AF than the Radeon HD 4670 512MB. (explain)

Radeon HD 6770 1GB		36000 Mtexels/sec
Radeon HD 4670 512MB		24000 Mtexels/sec
	Difference: 12000 (50%)

Pixel Rate

The Radeon HD 6770 1GB will be a lot (approximately 140%) more effective at full screen anti-aliasing than the Radeon HD 4670 512MB, and should be able to handle higher resolutions better. (explain)

Radeon HD 6770 1GB		14400 Mpixels/sec
Radeon HD 4670 512MB		6000 Mpixels/sec
	Difference: 8400 (140%)

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 megabytes per second) that can be transferred across the external memory interface in a second. The number is worked out by multiplying the interface width by its memory clock speed. If the card has DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total 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 texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.