Radeon HD 4650 512MB vs Radeon HD 6970

Intro

Compare those specs to the Radeon HD 6970, which has GPU core speed of 880 MHz, and 2048 MB of GDDR5 RAM running at 1375 MHz through a 256-bit bus. It also features 1536 Stream Processors, 96 TAUs, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4650 512MB		55 Watts
Radeon HD 6970		250 Watts
	Difference: 195 Watts (355%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6970 should in theory be a lot superior to the Radeon HD 4650 512MB overall. (explain)

Radeon HD 6970		176000 MB/sec
Radeon HD 4650 512MB		16000 MB/sec
	Difference: 160000 (1000%)

Texel Rate

The Radeon HD 6970 is a lot (approximately 340%) more effective at texture filtering than the Radeon HD 4650 512MB. (explain)

Radeon HD 6970		84480 Mtexels/sec
Radeon HD 4650 512MB		19200 Mtexels/sec
	Difference: 65280 (340%)

Pixel Rate

The Radeon HD 6970 will be quite a bit (approximately 487%) better at anti-aliasing than the Radeon HD 4650 512MB, and should be able to handle higher screen resolutions while still performing well. (explain)

Radeon HD 6970		28160 Mpixels/sec
Radeon HD 4650 512MB		4800 Mpixels/sec
	Difference: 23360 (487%)

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: Memory bandwidth is the maximum amount of information (measured in megabytes per second) that can be transferred across the external memory interface in one second. It's calculated by multiplying the bus width by its memory clock speed. In the case of DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the most 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 calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka 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, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.