GeForce GT 640 DDR3 vs GeForce GTX 550 Ti

Intro

Compare those specifications to the GeForce GTX 550 Ti, which comes with a GPU core clock speed of 900 MHz, and 1024 MB of GDDR5 memory set to run at 1026 MHz through a 192-bit bus. It also is comprised of 192 SPUs, 32 TAUs, and 24 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 550 Ti		1897 points
GeForce GT 640 DDR3		1560 points
	Difference: 337 (22%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GTX 550 Ti		116 Watts
	Difference: 51 Watts (78%)

Memory Bandwidth

As far as performance goes, the GeForce GTX 550 Ti should theoretically be much better than the GeForce GT 640 DDR3 overall. (explain)

GeForce GTX 550 Ti		98496 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 41472 (73%)

Texel Rate

Both cards have the exact same texel rate, so in theory they should be equally good at at anisotropic filtering. (explain)

Pixel Rate

The GeForce GTX 550 Ti should be quite a bit (approximately 50%) better at full screen anti-aliasing than the GeForce GT 640 DDR3, and also able to handle higher resolutions without losing too much performance. (explain)

GeForce GTX 550 Ti		21600 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 7200 (50%)

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 maximum amount of data (counted in MB per second) that can be transported past the external memory interface within a second. It is worked out by multiplying the interface width by its memory clock speed. If it uses DDR memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better 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 texture map elements (texels) that can be processed in one second. This is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The better 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 a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the the core 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 lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.