Radeon HD 3870 X2 1GB vs Radeon HD 5770

Intro

Compare that to the Radeon HD 5770, which uses a 40 nm design. AMD has set the core frequency at 850 MHz. The GDDR5 RAM works at a speed of 1200 MHz on this model. It features 800(160x5) SPUs as well as 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

The Radeon HD 3870 X2 1GB, in theory, should be a lot faster than the Radeon HD 5770 in general. (explain)

Radeon HD 3870 X2 1GB		144128 MB/sec
Radeon HD 5770		76800 MB/sec
	Difference: 67328 (88%)

Texel Rate

The Radeon HD 5770 is much (about 29%) more effective at texture filtering than the Radeon HD 3870 X2 1GB. (explain)

Radeon HD 5770		34000 Mtexels/sec
Radeon HD 3870 X2 1GB		26400 Mtexels/sec
	Difference: 7600 (29%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 3870 X2 1GB is a better choice, by a large margin. (explain)

Radeon HD 3870 X2 1GB		26400 Mpixels/sec
Radeon HD 5770		13600 Mpixels/sec
	Difference: 12800 (94%)

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: Memory bandwidth is the maximum amount of data (measured in MB per second) that can be moved across the external memory interface in a second. It's calculated by multiplying the card's interface width by its memory speed. If the card has DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better 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 can be processed per second. This is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at 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 the video card could possibly record to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.