Radeon HD 4850 1GB vs Radeon HD 6750

Intro

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

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6750		86 Watts
Radeon HD 4850 1GB		110 Watts
	Difference: 24 Watts (28%)

Memory Bandwidth

Theoretically, the Radeon HD 6750 should be a small bit faster than the Radeon HD 4850 1GB overall. (explain)

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

Texel Rate

The Radeon HD 6750 should be just a bit (approximately 4%) faster with regards to anisotropic filtering than the Radeon HD 4850 1GB. (explain)

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

Pixel Rate

The Radeon HD 6750 will be just a bit (more or less 16%) more effective at anti-aliasing than the Radeon HD 4850 1GB, and also will be able to handle higher screen resolutions better. (explain)

Radeon HD 6750		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: Bandwidth is the maximum amount of information (in units of megabytes per second) that can be moved across the external memory interface in one second. It's worked out by multiplying the bus width by its memory clock speed. If it uses DDR memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better 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 number is calculated by multiplying the total texture units by the core speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.