Radeon HD 3690/3830 vs Radeon HD 7990

Intro

Compare those specs to the Radeon HD 7990, which has core clock speeds of 950 MHz on the GPU, and 1500 MHz on the 3072 MB of GDDR5 memory. It features 2048 SPUs along with 128 TAUs and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3690/3830		75 Watts
Radeon HD 7990		375 Watts
	Difference: 300 Watts (400%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7990 is 2074% faster than the Radeon HD 3690/3830 overall, due to its higher data rate. (explain)

Radeon HD 7990		576000 MB/sec
Radeon HD 3690/3830		26496 MB/sec
	Difference: 549504 (2074%)

Texel Rate

The Radeon HD 7990 should be much (more or less 2175%) better at AF than the Radeon HD 3690/3830. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon HD 3690/3830		10688 Mtexels/sec
	Difference: 232512 (2175%)

Pixel Rate

The Radeon HD 7990 should be much (more or less 469%) better at full screen anti-aliasing than the Radeon HD 3690/3830, and should be capable of handling higher resolutions while still performing well. (explain)

Radeon HD 7990		60800 Mpixels/sec
Radeon HD 3690/3830		10688 Mpixels/sec
	Difference: 50112 (469%)

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 data (in units of MB per second) that can be transferred over the external memory interface in one second. It's worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total 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 number of pixels that the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of 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 is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.