Radeon HD 3870 X2 512MB vs Radeon HD 6750

Intro

Compare all that to the Radeon HD 6750, which features a core clock frequency of 725 MHz and a GDDR5 memory speed of 1000 MHz. It also uses a 128-bit memory bus, and uses a 40 nm design. It features 720 SPUs, 36 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon HD 3870 X2 512MB should be 80% faster than the Radeon HD 6750 overall, because of its greater data rate. (explain)

Radeon HD 3870 X2 512MB		115200 MB/sec
Radeon HD 6750		64000 MB/sec
	Difference: 51200 (80%)

Texel Rate

The Radeon HD 3870 X2 512MB should be a small bit (more or less 1%) more effective at AF than the Radeon HD 6750. (explain)

Radeon HD 3870 X2 512MB		26400 Mtexels/sec
Radeon HD 6750		26100 Mtexels/sec
	Difference: 300 (1%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon HD 3870 X2 512MB is the winner, and very much so. (explain)

Radeon HD 3870 X2 512MB		26400 Mpixels/sec
Radeon HD 6750		11600 Mpixels/sec
	Difference: 14800 (128%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of information (measured in MB per second) that can be moved past the external memory interface within a second. It's worked out by multiplying the bus width by its memory speed. In the case of DDR RAM, the result should be multiplied by 2 once 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 anti-aliasing, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.