Radeon HD 3870 512MB vs Radeon HD 4870 512MB

Intro

Compare those specs to the Radeon HD 4870 512MB, which has core speeds of 750 MHz on the GPU, and 900 MHz on the 512 MB of GDDR5 RAM. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 512MB		106 Watts
Radeon HD 4870 512MB		150 Watts
	Difference: 44 Watts (42%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4870 512MB should in theory be a lot superior to the Radeon HD 3870 512MB overall. (explain)

Radeon HD 4870 512MB		115200 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 57600 (100%)

Texel Rate

The Radeon HD 4870 512MB will be a lot (approximately 142%) better at texture filtering than the Radeon HD 3870 512MB. (explain)

Radeon HD 4870 512MB		30000 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 17600 (142%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 3870 512MB is the winner, but it probably won't make a huge difference. (explain)

Radeon HD 3870 512MB		12400 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 400 (3%)

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 maximum amount of information (in units of MB per second) that can be transferred across the external memory interface in a second. It's worked out by multiplying the bus width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 again. If it uses 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 high resolutions.

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

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.