GeForce GT 640 DDR3 vs GeForce GTX 1080

Intro

Compare those specs to the GeForce GTX 1080, which features GPU clock speed of 1607 MHz, and 8192 MB of GDDR5X memory set to run at 1251 MHz through a 256-bit bus. It also features 2560 SPUs, 160 Texture Address Units, and 64 Raster Operation 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

GeForce GTX 1080		21942 points
GeForce GT 640 DDR3		1560 points
	Difference: 20382 (1307%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GTX 1080		180 Watts
	Difference: 115 Watts (177%)

Memory Bandwidth

In theory, the GeForce GTX 1080 is 475% faster than the GeForce GT 640 DDR3 overall, because of its greater data rate. (explain)

GeForce GTX 1080		327680 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 270656 (475%)

Texel Rate

The GeForce GTX 1080 should be a lot (about 793%) better at AF than the GeForce GT 640 DDR3. (explain)

GeForce GTX 1080		257120 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 228320 (793%)

Pixel Rate

If running with a high resolution is important to you, then the GeForce GTX 1080 is a better choice, and very much so. (explain)

GeForce GTX 1080		102848 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 88448 (614%)

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: Memory bandwidth is the largest amount of information (counted in MB per second) that can be moved across the external memory interface within a second. It is calculated by multiplying the interface width by its memory clock speed. If the card has DDR memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.