GeForce GT 640 DDR3 vs GeForce GTX 980

Intro

Compare all of that to the GeForce GTX 980, which uses a 28 nm design. nVidia has set the core frequency at 1126 MHz. The GDDR5 memory is set to run at a speed of 1750 MHz on this particular model. It features 2048 SPUs along with 128 TAUs and 64 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

GeForce GTX 980		13552 points
GeForce GT 640 DDR3		1560 points
	Difference: 11992 (769%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GTX 980		165 Watts
	Difference: 100 Watts (154%)

Memory Bandwidth

In theory, the GeForce GTX 980 should perform much faster than the GeForce GT 640 DDR3 overall. (explain)

GeForce GTX 980		224000 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 166976 (293%)

Texel Rate

The GeForce GTX 980 will be a lot (approximately 400%) faster with regards to AF than the GeForce GT 640 DDR3. (explain)

GeForce GTX 980		144128 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 115328 (400%)

Pixel Rate

The GeForce GTX 980 should be a lot (more or less 400%) faster with regards to AA than the GeForce GT 640 DDR3, and also should be capable of handling higher screen resolutions without slowing down too much. (explain)

GeForce GTX 980		72064 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 57664 (400%)

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.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of information (counted in megabytes per second) that can be moved across the external memory interface in a second. It's worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR type memory, it must be multiplied by 2 once 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 high resolutions.

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

Pixel Rate: Pixel rate is the most pixels the video card can possibly record to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.