Radeon HD 4850 X2 512MB vs Radeon HD 6750 1GB

Intro

Compare those specs to the Radeon HD 6750 1GB, which comes with a core clock frequency of 725 MHz and a GDDR5 memory frequency of 1000 MHz. It also makes use of a 128-bit bus, and uses a 40 nm design. It is comprised of 720 SPUs, 36 TAUs, and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6750 1GB		86 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 164 Watts (191%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4850 X2 512MB should perform quite a bit faster than the Radeon HD 6750 1GB overall. (explain)

Radeon HD 4850 X2 512MB		127104 MB/sec
Radeon HD 6750 1GB		64000 MB/sec
	Difference: 63104 (99%)

Texel Rate

The Radeon HD 4850 X2 512MB will be quite a bit (more or less 92%) more effective at texture filtering than the Radeon HD 6750 1GB. (explain)

Radeon HD 4850 X2 512MB		50000 Mtexels/sec
Radeon HD 6750 1GB		26100 Mtexels/sec
	Difference: 23900 (92%)

Pixel Rate

The Radeon HD 4850 X2 512MB should be a lot (approximately 72%) more effective at anti-aliasing than the Radeon HD 6750 1GB, and should be able to handle higher resolutions more effectively. (explain)

Radeon HD 4850 X2 512MB		20000 Mpixels/sec
Radeon HD 6750 1GB		11600 Mpixels/sec
	Difference: 8400 (72%)

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 megabytes per second) that can be moved across the external memory interface in a second. The number is calculated by multiplying the interface width by the speed of its memory. In the case of DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better 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 can be processed per second. This figure is worked out by multiplying the total texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly record to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.