Radeon HD 3870 512MB vs Radeon HD 4830 512MB

Intro

Compare that to the Radeon HD 4830 512MB, which comes with core speeds of 575 MHz on the GPU, and 900 MHz on the 512 MB of GDDR3 memory. It features 640(128x5) SPUs as well as 32 TAUs and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 512MB		95 Watts
Radeon HD 3870 512MB		106 Watts
	Difference: 11 Watts (12%)

Memory Bandwidth

Both cards have exactly the same bandwidth, so theoretically they should perform exactly the same. (explain)

Texel Rate

The Radeon HD 4830 512MB should be much (about 48%) faster with regards to AF than the Radeon HD 3870 512MB. (explain)

Radeon HD 4830 512MB		18400 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 6000 (48%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 3870 512MB is superior to the Radeon HD 4830 512MB, by a large margin. (explain)

Radeon HD 3870 512MB		12400 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 3200 (35%)

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 information (in units of MB per second) that can be transported over the external memory interface in a second. The number is worked out by multiplying the card's bus width by its memory speed. In the case of DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the 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 texture map elements (texels) that are processed per second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the video 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 number of pixels that the graphics chip can possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of 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 is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.