GeForce GT 640 DDR3 vs Radeon HD 4670 512MB

Intro

Compare those specifications to the Radeon HD 4670 512MB, which uses a 55 nm design. AMD has clocked the core frequency at 750 MHz. The GDDR4/GDDR3/DDR3/DDR2 RAM works at a speed of 1000 MHz on this particular card. It features 320(64x5) SPUs as well as 32 Texture Address Units and 8 Rasterization Operator 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, in theory, should perform a lot faster than the Radeon HD 4670 512MB overall. (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 is a small bit (more or less 20%) more effective at texture 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

The GeForce GT 640 DDR3 will be a lot (about 140%) more effective at FSAA than the Radeon HD 4670 512MB, and able to handle higher resolutions while still performing well. (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: Bandwidth is the max amount of information (in units of MB per second) that can be moved past the external memory interface in a second. It's worked out by multiplying the interface width by its memory clock speed. If it uses DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the most pixels the video card can possibly record to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.