Radeon HD 4750 vs Radeon HD 6870

Intro

Compare those specs to the Radeon HD 6870, which features a clock speed of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also uses a 256-bit memory bus, and uses a 40 nm design. It features 1120 SPUs, 56 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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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

Theoretically speaking, the Radeon HD 6870 should perform a lot 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 a lot (about 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

The Radeon HD 6870 will be a lot (more or less 147%) better at anti-aliasing than the Radeon HD 4750, and will be capable of handling higher screen resolutions while still performing well. (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 information (counted in megabytes per second) that can be moved over the external memory interface in one second. It's worked out by multiplying the interface width by its memory speed. If it uses DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.