GeForce GT 640 DDR3 vs Radeon HD 7950

Intro

Compare those specs to the Radeon HD 7950, which has GPU clock speed of 800 MHz, and 1536 MB of GDDR5 RAM set to run at 1250 MHz through a 384-bit bus. It also is comprised of 1792 SPUs, 112 TAUs, and 32 Raster Operation 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

Radeon HD 7950		7731 points
GeForce GT 640 DDR3		1560 points
	Difference: 6171 (396%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
Radeon HD 7950		200 Watts
	Difference: 135 Watts (208%)

Memory Bandwidth

As far as performance goes, the Radeon HD 7950 should in theory be quite a bit better than the GeForce GT 640 DDR3 overall. (explain)

Radeon HD 7950		240000 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 182976 (321%)

Texel Rate

The Radeon HD 7950 is quite a bit (approximately 211%) faster with regards to texture filtering than the GeForce GT 640 DDR3. (explain)

Radeon HD 7950		89600 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 60800 (211%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 7950 is superior to the GeForce GT 640 DDR3, and very much so. (explain)

Radeon HD 7950		25600 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 11200 (78%)

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 maximum amount of data (measured in megabytes per second) that can be transferred across the external memory interface in one second. The number is worked out by multiplying the bus width by its memory speed. In the case of DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

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