Radeon HD 3850 X2 vs Radeon HD 7990

Intro

Compare those specs to the Radeon HD 7990, which has GPU core speed of 950 MHz, and 3072 MB of GDDR5 memory running at 1500 MHz through a 384-bit bus. It also features 2048 Stream Processors, 128 TAUs, and 32 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon HD 7990 should be much faster than the Radeon HD 3850 X2 overall. (explain)

Radeon HD 7990		576000 MB/sec
Radeon HD 3850 X2		105984 MB/sec
	Difference: 470016 (443%)

Texel Rate

The Radeon HD 7990 should be much (more or less 1038%) more effective at AF than the Radeon HD 3850 X2. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon HD 3850 X2		21376 Mtexels/sec
	Difference: 221824 (1038%)

Pixel Rate

The Radeon HD 7990 will be quite a bit (more or less 184%) more effective at anti-aliasing than the Radeon HD 3850 X2, and should be capable of handling higher resolutions without slowing down too much. (explain)

Radeon HD 7990		60800 Mpixels/sec
Radeon HD 3850 X2		21376 Mpixels/sec
	Difference: 39424 (184%)

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 max amount of data (counted in megabytes per second) that can be transported past the external memory interface in one second. It is calculated by multiplying the card's interface width by the speed of its memory. If it uses DDR memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, 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 texture map elements (texels) that can be applied in one second. This is worked out by multiplying the total texture units of the card 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 most pixels the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out 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 filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.