GeForce GTX 660 vs Radeon HD 6990

Intro

Compare all of that to the Radeon HD 6990, which has a GPU core clock speed of 830 MHz, and 2048 MB of GDDR5 memory set to run at 1250 MHz through a 256-bit bus. It also is comprised of 1536 SPUs, 96 Texture Address Units, and 32 ROPs.

Display Graphs

Hide Graphs

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 6990		5820 points
GeForce GTX 660		5063 points
	Difference: 757 (15%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 660		140 Watts
Radeon HD 6990		375 Watts
	Difference: 235 Watts (168%)

Memory Bandwidth

The Radeon HD 6990, in theory, should perform quite a bit faster than the GeForce GTX 660 overall. (explain)

Radeon HD 6990		320000 MB/sec
GeForce GTX 660		144192 MB/sec
	Difference: 175808 (122%)

Texel Rate

The Radeon HD 6990 should be a lot (more or less 103%) more effective at AF than the GeForce GTX 660. (explain)

Radeon HD 6990		159360 Mtexels/sec
GeForce GTX 660		78400 Mtexels/sec
	Difference: 80960 (103%)

Pixel Rate

The Radeon HD 6990 should be much (about 126%) more effective at FSAA than the GeForce GTX 660, and also will be capable of handling higher screen resolutions better. (explain)

Radeon HD 6990		53120 Mpixels/sec
GeForce GTX 660		23520 Mpixels/sec
	Difference: 29600 (126%)

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 max amount of information (measured in megabytes per second) that can be transported over the external memory interface within a second. It's worked out by multiplying the card's interface width by its memory speed. In the case of DDR memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.