Radeon HD 4870 2GB vs Radeon HD 6750

Intro

Compare that to the Radeon HD 6750, which uses a 40 nm design. AMD has set the core speed at 725 MHz. The GDDR5 RAM runs at a frequency of 1000 MHz on this specific card. It features 720 SPUs along with 36 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6750		86 Watts
Radeon HD 4870 2GB		150 Watts
	Difference: 64 Watts (74%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4870 2GB should theoretically be a lot superior to the Radeon HD 6750 in general. (explain)

Radeon HD 4870 2GB		115200 MB/sec
Radeon HD 6750		64000 MB/sec
	Difference: 51200 (80%)

Texel Rate

The Radeon HD 4870 2GB should be a little bit (approximately 15%) better at anisotropic filtering than the Radeon HD 6750. (explain)

Radeon HD 4870 2GB		30000 Mtexels/sec
Radeon HD 6750		26100 Mtexels/sec
	Difference: 3900 (15%)

Pixel Rate

The Radeon HD 4870 2GB will be a bit (about 3%) faster with regards to anti-aliasing than the Radeon HD 6750, and also should be able to handle higher screen resolutions while still performing well. (explain)

Radeon HD 4870 2GB		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 (measured in MB per second) that can be moved across the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory speed. If the card has DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total number of texture units by the core speed of the chip. The higher 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 the graphics card could possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.