Radeon HD 3870 512MB vs Radeon HD 4830 1GB

Intro

Compare all of that to the Radeon HD 4830 1GB, which makes use of a 55 nm design. AMD has set the core frequency at 575 MHz. The GDDR4 RAM is set to run at a speed of 900 MHz on this model. It features 640(128x5) SPUs along with 32 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 1GB		95 Watts
Radeon HD 3870 512MB		106 Watts
	Difference: 11 Watts (12%)

Memory Bandwidth

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

Texel Rate

The Radeon HD 4830 1GB will be quite a bit (more or less 48%) better at AF than the Radeon HD 3870 512MB. (explain)

Radeon HD 4830 1GB		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 1GB, by far. (explain)

Radeon HD 3870 512MB		12400 Mpixels/sec
Radeon HD 4830 1GB		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: Bandwidth is the max amount of data (in units of MB per second) that can be transferred over the external memory interface in a second. The number is calculated by multiplying the card's interface width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This is calculated by multiplying the total number of texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated 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 drawing the pixels (image) on the screen. The actual pixel rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.