GeForce GT 640 DDR3 vs Radeon HD 4670 512MB

Intro

Compare those specs to the Radeon HD 4670 512MB, which comes with a core clock speed of 750 MHz and a GDDR4/GDDR3/DDR3/DDR2 memory speed of 1000 MHz. It also features a 128-bit bus, and uses a 55 nm design. It is comprised of 320(64x5) SPUs, 32 TAUs, and 8 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
Radeon HD 4670 512MB		70 Watts
	Difference: 5 Watts (8%)

Memory Bandwidth

The GeForce GT 640 DDR3 should in theory perform a lot faster than the Radeon HD 4670 512MB in general. (explain)

GeForce GT 640 DDR3		57024 MB/sec
Radeon HD 4670 512MB		32000 MB/sec
	Difference: 25024 (78%)

Texel Rate

The GeForce GT 640 DDR3 will be a bit (approximately 20%) faster with regards to anisotropic filtering than the Radeon HD 4670 512MB. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
Radeon HD 4670 512MB		24000 Mtexels/sec
	Difference: 4800 (20%)

Pixel Rate

If using a high screen resolution is important to you, then the GeForce GT 640 DDR3 is the winner, by a large margin. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
Radeon HD 4670 512MB		6000 Mpixels/sec
	Difference: 8400 (140%)

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 (in units of MB per second) that can be transported over the external memory interface in a second. It's calculated by multiplying the interface width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, 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 can be processed per second. This figure is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.