Radeon HD 6990 vs Radeon HD 7870 XT

Intro

Compare those specs to the Radeon HD 7870 XT, which comes with core clock speeds of 925 MHz on the GPU, and 1500 MHz on the 2048 MB of GDDR5 memory. It features 1536 SPUs along with 96 Texture Address Units 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 7870 XT		6390 points
Radeon HD 6990		5820 points
	Difference: 570 (10%)

Ethereum Mining Hash Rate

Radeon HD 6990		24 Mh/s
Radeon HD 7870 XT		15 Mh/s
	Difference: 9 (60%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7870 XT		185 Watts
Radeon HD 6990		375 Watts
	Difference: 190 Watts (103%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6990 should theoretically be much better than the Radeon HD 7870 XT in general. (explain)

Radeon HD 6990		320000 MB/sec
Radeon HD 7870 XT		192000 MB/sec
	Difference: 128000 (67%)

Texel Rate

The Radeon HD 6990 will be a lot (about 79%) more effective at AF than the Radeon HD 7870 XT. (explain)

Radeon HD 6990		159360 Mtexels/sec
Radeon HD 7870 XT		88800 Mtexels/sec
	Difference: 70560 (79%)

Pixel Rate

The Radeon HD 6990 should be much (approximately 79%) better at anti-aliasing than the Radeon HD 7870 XT, and able to handle higher screen resolutions better. (explain)

Radeon HD 6990		53120 Mpixels/sec
Radeon HD 7870 XT		29600 Mpixels/sec
	Difference: 23520 (79%)

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 information (in units of MB per second) that can be moved over the external memory interface in one second. The number is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR memory, it must be multiplied by 2 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, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the video 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 amount of pixels the video card can possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes 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, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.