Radeon HD 6990 vs Radeon R7 250X 2GB

Intro

Compare those specs to the Radeon R7 250X 2GB, which comes with a core clock speed of 1000 MHz and a GDDR5 memory frequency of 1125 MHz. It also features a 128-bit memory bus, and makes use of a 28 nm design. It features 640 SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R7 250X 2GB		95 Watts
Radeon HD 6990		375 Watts
	Difference: 280 Watts (295%)

Memory Bandwidth

Theoretically, the Radeon HD 6990 should perform much faster than the Radeon R7 250X 2GB overall. (explain)

Radeon HD 6990		320000 MB/sec
Radeon R7 250X 2GB		72000 MB/sec
	Difference: 248000 (344%)

Texel Rate

The Radeon HD 6990 will be quite a bit (about 298%) faster with regards to texture filtering than the Radeon R7 250X 2GB. (explain)

Radeon HD 6990		159360 Mtexels/sec
Radeon R7 250X 2GB		40000 Mtexels/sec
	Difference: 119360 (298%)

Pixel Rate

The Radeon HD 6990 will be quite a bit (approximately 232%) faster with regards to FSAA than the Radeon R7 250X 2GB, and able to handle higher resolutions without slowing down too much. (explain)

Radeon HD 6990		53120 Mpixels/sec
Radeon R7 250X 2GB		16000 Mpixels/sec
	Difference: 37120 (232%)

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 (measured in MB per second) that can be transferred past the external memory interface in one second. It's calculated by multiplying the card's interface width by its memory speed. If the card has DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total number of texture units by the core speed of the chip. The higher the texel rate, the better the 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 that the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units 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 fill 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 max fill rate.