Join Us On Facebook

Compare any two graphics cards:
VS

GeForce GT 640 DDR3 vs GeForce GTX 580 3GB

Intro

The GeForce GT 640 DDR3 features a clock frequency of 900 MHz and a DDR3 memory frequency of 1782 MHz. It also uses a 128-bit memory bus, and uses a 28 nm design. It features 384 SPUs, 32 Texture Address Units, and 16 ROPs.

Compare all that to the GeForce GTX 580 3GB, which has GPU core speed of 772 MHz, and 3072 MB of GDDR5 memory running at 1002 MHz through a 384-bit bus. It also is made up of 512 SPUs, 64 TAUs, and 48 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3 65 Watts
GeForce GTX 580 3GB 244 Watts
Difference: 179 Watts (275%)

Memory Bandwidth

Theoretically, the GeForce GTX 580 3GB should be much faster than the GeForce GT 640 DDR3 overall. (explain)

GeForce GTX 580 3GB 192384 MB/sec
GeForce GT 640 DDR3 57024 MB/sec
Difference: 135360 (237%)

Texel Rate

The GeForce GTX 580 3GB is a lot (more or less 72%) more effective at AF than the GeForce GT 640 DDR3. (explain)

GeForce GTX 580 3GB 49408 Mtexels/sec
GeForce GT 640 DDR3 28800 Mtexels/sec
Difference: 20608 (72%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the GeForce GTX 580 3GB is a better choice, by a large margin. (explain)

GeForce GTX 580 3GB 37056 Mpixels/sec
GeForce GT 640 DDR3 14400 Mpixels/sec
Difference: 22656 (157%)

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

GeForce GT 640 DDR3

Amazon.com

GeForce GTX 580 3GB

Amazon.com

Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.

Specifications

Model GeForce GT 640 DDR3 GeForce GTX 580 3GB
Manufacturer nVidia nVidia
Year June 2012 November 2010
Code Name GK107 GF110
Fab Process 28 nm 40 nm
Bus PCIe 3.0 x16 PCIe x16
Memory 2048 MB 3072 MB
Core Speed 900 MHz 772 MHz
Shader Speed 900 MHz 1544 MHz
Memory Speed 1782 MHz (3564 MHz effective) 1002 MHz (4008 MHz effective)
Unified Shaders 384 512
Texture Mapping Units 32 64
Render Output Units 16 48
Bus Type DDR3 GDDR5
Bus Width 128-bit 384-bit
DirectX Version DirectX 11.0 DirectX 11
OpenGL Version OpenGL 4.2 OpenGL 4.1
Power (Max TDP) 65 watts 244 watts
Shader Model 5.0 5.0
Bandwidth 57024 MB/sec 192384 MB/sec
Texel Rate 28800 Mtexels/sec 49408 Mtexels/sec
Pixel Rate 14400 Mpixels/sec 37056 Mpixels/sec

Memory Bandwidth: Memory bandwidth is the maximum amount of data (counted in megabytes per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the card's interface width by its memory speed. If the card has DDR type 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 anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour 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 also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.

Comments

Be the first to leave a comment!

Your email address will not be published.


You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

Spam Protection by WP-SpamFree