GeForce GTX 660 Ti vs Radeon HD 6990

Intro

Compare that to the Radeon HD 6990, which comes with a clock frequency of 830 MHz and a GDDR5 memory speed of 1250 MHz. It also makes use of a 256-bit memory bus, and makes use of a 40 nm design. It is made up of 1536 SPUs, 96 TAUs, 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

GeForce GTX 660 Ti		6013 points
Radeon HD 6990		5820 points
	Difference: 193 (3%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 660 Ti		150 Watts
Radeon HD 6990		375 Watts
	Difference: 225 Watts (150%)

Memory Bandwidth

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

Radeon HD 6990		320000 MB/sec
GeForce GTX 660 Ti		144000 MB/sec
	Difference: 176000 (122%)

Texel Rate

The Radeon HD 6990 will be much (approximately 56%) better at anisotropic filtering than the GeForce GTX 660 Ti. (explain)

Radeon HD 6990		159360 Mtexels/sec
GeForce GTX 660 Ti		102480 Mtexels/sec
	Difference: 56880 (56%)

Pixel Rate

The Radeon HD 6990 is quite a bit (approximately 142%) more effective at full screen anti-aliasing than the GeForce GTX 660 Ti, and able to handle higher screen resolutions without losing too much performance. (explain)

Radeon HD 6990		53120 Mpixels/sec
GeForce GTX 660 Ti		21960 Mpixels/sec
	Difference: 31160 (142%)

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 (in units of MB per second) that can be transferred over the external memory interface in a second. The number is worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly record to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.