Radeon HD 4650 1GB vs Radeon HD 6950

Intro

Compare those specs to the Radeon HD 6950, which makes use of a 40 nm design. AMD has set the core speed at 800 MHz. The GDDR5 memory works at a speed of 1250 MHz on this specific card. It features 1408 SPUs along with 88 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4650 1GB		55 Watts
Radeon HD 6950		200 Watts
	Difference: 145 Watts (264%)

Memory Bandwidth

Theoretically, the Radeon HD 6950 should be a lot faster than the Radeon HD 4650 1GB overall. (explain)

Radeon HD 6950		160000 MB/sec
Radeon HD 4650 1GB		22400 MB/sec
	Difference: 137600 (614%)

Texel Rate

The Radeon HD 6950 will be quite a bit (more or less 267%) more effective at anisotropic filtering than the Radeon HD 4650 1GB. (explain)

Radeon HD 6950		70400 Mtexels/sec
Radeon HD 4650 1GB		19200 Mtexels/sec
	Difference: 51200 (267%)

Pixel Rate

The Radeon HD 6950 should be a lot (about 433%) better at AA than the Radeon HD 4650 1GB, and able to handle higher screen resolutions more effectively. (explain)

Radeon HD 6950		25600 Mpixels/sec
Radeon HD 4650 1GB		4800 Mpixels/sec
	Difference: 20800 (433%)

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 MB per second) that can be transferred across the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. In the case of DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This 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 applied per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as 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 potential to reach the max fill rate.