Radeon HD 3870 512MB vs Radeon HD 4730

Intro

Compare those specs to the Radeon HD 4730, which features GPU clock speed of 700 MHz, and 512 MB of GDDR5 memory running at 900 MHz through a 128-bit bus. It also is comprised of 640(128x5) SPUs, 32 Texture Address Units, and 8 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 512MB		106 Watts
Radeon HD 4730		140 Watts
	Difference: 34 Watts (32%)

Memory Bandwidth

Both cards have exactly the same bandwidth, so in theory they should have identical performance. (explain)

Texel Rate

The Radeon HD 4730 will be quite a bit (approximately 81%) faster with regards to texture filtering than the Radeon HD 3870 512MB. (explain)

Radeon HD 4730		22400 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 10000 (81%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 3870 512MB is a better choice, by far. (explain)

Radeon HD 3870 512MB		12400 Mpixels/sec
Radeon HD 4730		5600 Mpixels/sec
	Difference: 6800 (121%)

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 megabytes per second) that can be transported across the external memory interface within a second. It is worked out by multiplying the interface width by its memory speed. If it uses DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This number is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video 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 number of pixels that the graphics 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 colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called 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 of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.