Radeon HD 6990 vs Radeon HD 7990

Intro

Compare those specs to the Radeon HD 7990, which has GPU clock speed of 950 MHz, and 3072 MB of GDDR5 RAM running at 1500 MHz through a 384-bit bus. It also is comprised of 2048 SPUs, 128 Texture Address Units, and 32 ROPs.

Display Graphs

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Benchmarks

These are real-world performance benchmarks that were submitted by Hardware Compare users. The scores seen here are the average of all benchmarks submitted for each respective test and hardware.

3DMark Fire Strike Graphics Score

Radeon HD 7990		15520 points
Radeon HD 6990		5820 points
	Difference: 9700 (167%)

Ethereum Mining Hash Rate

Radeon HD 7990		32 Mh/s
Radeon HD 6990		24 Mh/s
	Difference: 8 (33%)

Power Usage and Theoretical Benchmarks

Both cards have the same power consumption.

Memory Bandwidth

Theoretically, the Radeon HD 7990 should perform a lot faster than the Radeon HD 6990 in general. (explain)

Radeon HD 7990		576000 MB/sec
Radeon HD 6990		320000 MB/sec
	Difference: 256000 (80%)

Texel Rate

The Radeon HD 7990 is a lot (more or less 53%) more effective at anisotropic filtering than the Radeon HD 6990. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon HD 6990		159360 Mtexels/sec
	Difference: 83840 (53%)

Pixel Rate

The Radeon HD 7990 is a small bit (about 14%) better at FSAA than the Radeon HD 6990, and should be able to handle higher screen resolutions more effectively. (explain)

Radeon HD 7990		60800 Mpixels/sec
Radeon HD 6990		53120 Mpixels/sec
	Difference: 7680 (14%)

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 largest amount of data (in units of MB per second) that can be transported over the external memory interface in a second. It is worked out by multiplying the interface width by the speed of its memory. If it uses DDR type memory, it must 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 AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant 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.