Radeon HD 6990 vs Radeon HD 7990

Intro

Compare those specifications to the Radeon HD 7990, which makes use of a 28 nm design. AMD has set the core speed at 950 MHz. The GDDR5 RAM is set to run at a frequency of 1500 MHz on this specific model. It features 2048 SPUs along with 128 TAUs and 32 Rasterization Operator Units.

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 speaking, the Radeon HD 7990 should perform quite a bit faster than the Radeon HD 6990 overall. (explain)

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

Texel Rate

The Radeon HD 7990 should be quite a bit (approximately 53%) better 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 little bit (approximately 14%) better at AA than the Radeon HD 6990, and also should be capable of handling higher 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 maximum amount of data (in units of megabytes per second) that can be transported over 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 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster 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 can be applied in one 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 the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the the core speed of the card. 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 output rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.