GeForce GT 640 DDR3 vs Radeon HD 6990

Intro

Compare those specs to the Radeon HD 6990, which makes use of a 40 nm design. AMD has set the core frequency at 830 MHz. The GDDR5 memory is set to run at a frequency of 1250 MHz on this model. It features 1536 SPUs along with 96 Texture Address Units and 32 Rasterization Operator Units.

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 GT 640 DDR3		1560 points
	Difference: 4260 (273%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
Radeon HD 6990		375 Watts
	Difference: 310 Watts (477%)

Memory Bandwidth

In theory, the Radeon HD 6990 should be 461% faster than the GeForce GT 640 DDR3 overall, due to its greater data rate. (explain)

Radeon HD 6990		320000 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 262976 (461%)

Texel Rate

The Radeon HD 6990 is much (about 453%) more effective at texture filtering than the GeForce GT 640 DDR3. (explain)

Radeon HD 6990		159360 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 130560 (453%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 6990 is the winner, by far. (explain)

Radeon HD 6990		53120 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 38720 (269%)

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 information (measured in megabytes per second) that can be transported across the external memory interface in a second. It is calculated by multiplying the interface width by the speed of its memory. If the card has DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This is worked out by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the graphics 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 most pixels that the graphics chip can possibly record to its local memory in one 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 filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.