GeForce GT 640 DDR3 vs Radeon HD 7970

Intro

Compare those specs to the Radeon HD 7970, which comes with a GPU core clock speed of 925 MHz, and 3072 MB of GDDR5 memory set to run at 1375 MHz through a 384-bit bus. It also is comprised of 2048 Stream Processors, 128 TAUs, and 32 ROPs.

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

Radeon HD 7970		8225 points
GeForce GT 640 DDR3		1560 points
	Difference: 6665 (427%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
Radeon HD 7970		250 Watts
	Difference: 185 Watts (285%)

Memory Bandwidth

The Radeon HD 7970, in theory, should perform much faster than the GeForce GT 640 DDR3 in general. (explain)

Radeon HD 7970		264000 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 206976 (363%)

Texel Rate

The Radeon HD 7970 is a lot (about 311%) faster with regards to anisotropic filtering than the GeForce GT 640 DDR3. (explain)

Radeon HD 7970		118400 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 89600 (311%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 7970 is superior to the GeForce GT 640 DDR3, and very much so. (explain)

Radeon HD 7970		29600 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 15200 (106%)

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 largest amount of information (in units of megabytes per second) that can be transferred across the external memory interface in a second. It is calculated by multiplying the card's bus width by its memory speed. If it uses DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This is worked out by multiplying the total amount of texture units 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 most pixels that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.