Radeon HD 3870 512MB vs Radeon HD 4890 1GB

Intro

Compare all of that to the Radeon HD 4890 1GB, which has core speeds of 1000 MHz on the GPU, and 975 MHz on the 1024 MB of GDDR5 RAM. It features 800(160x5) SPUs as well as 40 Texture Address Units 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 4890 1GB		190 Watts
	Difference: 84 Watts (79%)

Memory Bandwidth

As far as performance goes, the Radeon HD 4890 1GB should theoretically be a lot better than the Radeon HD 3870 512MB in general. (explain)

Radeon HD 4890 1GB		124800 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 67200 (117%)

Texel Rate

The Radeon HD 4890 1GB should be quite a bit (more or less 223%) better at texture filtering than the Radeon HD 3870 512MB. (explain)

Radeon HD 4890 1GB		40000 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 27600 (223%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 4890 1GB is superior to the Radeon HD 3870 512MB, by far. (explain)

Radeon HD 4890 1GB		16000 Mpixels/sec
Radeon HD 3870 512MB		12400 Mpixels/sec
	Difference: 3600 (29%)

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 (measured in megabytes per second) that can be transferred across the external memory interface in a second. It's worked out by multiplying the interface width by its memory speed. If the card has DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to the local memory in a 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 - aka 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.