Radeon HD 4850 1GB vs Radeon HD 6750 1GB

Intro

Compare those specifications to the Radeon HD 6750 1GB, which makes use of a 40 nm design. ATi has clocked the core speed at 725 MHz. The GDDR5 memory is set to run at a frequency of 1000 MHz on this model. It features 720 SPUs as well as 36 TAUs and 16 Rasterization Operator Units.

(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 1GB		110 Watts
	Difference: 24 Watts (28%)

Memory Bandwidth

In theory, the Radeon HD 6750 1GB is 1% quicker than the Radeon HD 4850 1GB overall, due to its higher data rate. (explain)

Radeon HD 6750 1GB		64000 MB/sec
Radeon HD 4850 1GB		63552 MB/sec
	Difference: 448 (1%)

Texel Rate

The Radeon HD 6750 1GB should be a little bit (more or less 4%) better at texture filtering than the Radeon HD 4850 1GB. (explain)

Radeon HD 6750 1GB		26100 Mtexels/sec
Radeon HD 4850 1GB		25000 Mtexels/sec
	Difference: 1100 (4%)

Pixel Rate

The Radeon HD 6750 1GB will be a bit (about 16%) faster with regards to FSAA than the Radeon HD 4850 1GB, and will be able to handle higher screen resolutions more effectively. (explain)

Radeon HD 6750 1GB		11600 Mpixels/sec
Radeon HD 4850 1GB		10000 Mpixels/sec
	Difference: 1600 (16%)

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: Memory bandwidth is the max amount of data (in units of MB per second) that can be transported across the external memory interface in one second. The number is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher 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 are applied in one second. This figure is calculated by multiplying the total amount of 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 texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the core 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 also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.