Radeon HD 3870 X2 1GB vs Radeon HD 5770

Intro

Compare all that to the Radeon HD 5770, which uses a 40 nm design. AMD has clocked the core frequency at 850 MHz. The GDDR5 RAM works at a frequency of 1200 MHz on this particular card. 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

In theory, the Radeon HD 3870 X2 1GB 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 should be a lot (about 29%) faster with regards to 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 using a high screen resolution is important to you, then the Radeon HD 3870 X2 1GB is a better choice, by far. (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: Bandwidth is the largest amount of data (counted in MB per second) that can be transported past the external memory interface within a second. It is calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR memory, it should 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, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.