Radeon HD 4870 512MB vs Radeon HD 6750

Intro

Compare those specs to the Radeon HD 6750, which has GPU clock speed of 725 MHz, and 512 MB of GDDR5 RAM set to run at 1000 MHz through a 128-bit bus. It also is made up of 720 SPUs, 36 TAUs, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

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

Memory Bandwidth

In theory, the Radeon HD 4870 512MB will be 80% quicker than the Radeon HD 6750 in general, because of its higher data rate. (explain)

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

Texel Rate

The Radeon HD 4870 512MB will be a bit (approximately 15%) more effective at texture filtering than the Radeon HD 6750. (explain)

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

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 4870 512MB is a better choice, though not by far. (explain)

Radeon HD 4870 512MB		12000 Mpixels/sec
Radeon HD 6750		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 max amount of information (counted in MB per second) that can be transported over the external memory interface in a second. The number is worked out by multiplying the bus width by its memory clock speed. In the case of DDR type memory, 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, High Dynamic Range 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 number is calculated by multiplying the total texture units by the core clock speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly record to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). 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 max fill rate.