Radeon HD 4750 vs Radeon HD 6870

Intro

Compare all of that to the Radeon HD 6870, which uses a 40 nm design. AMD has set the core speed at 900 MHz. The GDDR5 RAM runs at a frequency of 1050 MHz on this particular model. It features 1120 SPUs as well as 56 Texture Address Units and 32 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4750		75 Watts
Radeon HD 6870		151 Watts
	Difference: 76 Watts (101%)

Memory Bandwidth

The Radeon HD 6870, in theory, should perform much faster than the Radeon HD 4750 in general. (explain)

Radeon HD 6870		134400 MB/sec
Radeon HD 4750		51200 MB/sec
	Difference: 83200 (163%)

Texel Rate

The Radeon HD 6870 is quite a bit (approximately 116%) better at AF than the Radeon HD 4750. (explain)

Radeon HD 6870		50400 Mtexels/sec
Radeon HD 4750		23360 Mtexels/sec
	Difference: 27040 (116%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 6870 is the winner, by far. (explain)

Radeon HD 6870		28800 Mpixels/sec
Radeon HD 4750		11680 Mpixels/sec
	Difference: 17120 (147%)

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 data (in units of MB per second) that can be moved over the external memory interface in one second. It's calculated by multiplying the card's interface width by the speed of its memory. If it uses DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, 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 is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. 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 reach the max fill rate.