Radeon HD 4870 512MB vs Radeon HD 6750 1GB

Intro

Compare all that to the Radeon HD 6750 1GB, which comes with a GPU core clock speed of 725 MHz, and 1024 MB of GDDR5 memory set to run at 1000 MHz through a 128-bit bus. It also features 720 Stream Processors, 36 TAUs, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6750 1GB		86 Watts
Radeon HD 4870 512MB		150 Watts
	Difference: 64 Watts (74%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4870 512MB should theoretically be much better than the Radeon HD 6750 1GB overall. (explain)

Radeon HD 4870 512MB		115200 MB/sec
Radeon HD 6750 1GB		64000 MB/sec
	Difference: 51200 (80%)

Texel Rate

The Radeon HD 4870 512MB will be a small bit (approximately 15%) more effective at AF than the Radeon HD 6750 1GB. (explain)

Radeon HD 4870 512MB		30000 Mtexels/sec
Radeon HD 6750 1GB		26100 Mtexels/sec
	Difference: 3900 (15%)

Pixel Rate

The Radeon HD 4870 512MB should be a small bit (about 3%) more effective at full screen anti-aliasing than the Radeon HD 6750 1GB, and also will be able to handle higher screen resolutions more effectively. (explain)

Radeon HD 4870 512MB		12000 Mpixels/sec
Radeon HD 6750 1GB		11600 Mpixels/sec
	Difference: 400 (3%)

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 maximum amount of data (measured in MB per second) that can be moved over the external memory interface in a second. It's calculated by multiplying the bus width by its memory speed. In the case of DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster 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 are processed in one second. This number is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.