Radeon HD 3850 1GB vs Radeon HD 3870 X2 512MB

Intro

Compare all of that to the Radeon HD 3870 X2 512MB, which has a clock speed of 825 MHz and a GDDR3 memory frequency of 900 MHz. It also features a 256-bit bus, and makes use of a 55 nm design. It is made up of 320(64x5) SPUs, 16 Texture Address Units, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

As far as performance goes, the Radeon HD 3870 X2 512MB should in theory be much superior to the Radeon HD 3850 1GB in general. (explain)

Radeon HD 3870 X2 512MB		115200 MB/sec
Radeon HD 3850 1GB		52992 MB/sec
	Difference: 62208 (117%)

Texel Rate

The Radeon HD 3870 X2 512MB is quite a bit (more or less 147%) better at AF than the Radeon HD 3850 1GB. (explain)

Radeon HD 3870 X2 512MB		26400 Mtexels/sec
Radeon HD 3850 1GB		10688 Mtexels/sec
	Difference: 15712 (147%)

Pixel Rate

The Radeon HD 3870 X2 512MB will be quite a bit (more or less 147%) more effective at AA than the Radeon HD 3850 1GB, and also will be capable of handling higher resolutions better. (explain)

Radeon HD 3870 X2 512MB		26400 Mpixels/sec
Radeon HD 3850 1GB		10688 Mpixels/sec
	Difference: 15712 (147%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the maximum amount of information (counted in megabytes per second) that can be moved over the external memory interface in one second. It's calculated by multiplying the bus width by the speed of its memory. In the case of DDR memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the 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 can be applied in one 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 graphics 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 amount of pixels the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.