GeForce GT 640 DDR3 vs Radeon HD 3850 1GB

Intro

Compare those specs to the Radeon HD 3850 1GB, which features a core clock frequency of 668 MHz and a GDDR3 memory speed of 828 MHz. It also uses a 256-bit memory bus, and makes use of a 55 nm design. It is comprised of 320(64x5) SPUs, 16 TAUs, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
Radeon HD 3850 1GB		75 Watts
	Difference: 10 Watts (15%)

Memory Bandwidth

As far as performance goes, the GeForce GT 640 DDR3 should in theory be just a bit superior to the Radeon HD 3850 1GB in general. (explain)

GeForce GT 640 DDR3		57024 MB/sec
Radeon HD 3850 1GB		52992 MB/sec
	Difference: 4032 (8%)

Texel Rate

The GeForce GT 640 DDR3 will be a lot (approximately 169%) faster with regards to anisotropic filtering than the Radeon HD 3850 1GB. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
Radeon HD 3850 1GB		10688 Mtexels/sec
	Difference: 18112 (169%)

Pixel Rate

If running with a high resolution is important to you, then the GeForce GT 640 DDR3 is the winner, by far. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
Radeon HD 3850 1GB		10688 Mpixels/sec
	Difference: 3712 (35%)

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 information (measured in megabytes per second) that can be transferred across the external memory interface within a second. The number is calculated by multiplying the interface width by the speed of its memory. In the case of DDR type RAM, it should be multiplied by 2 again. If 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 amount of texture map elements (texels) that are applied per second. This is worked out by multiplying the total texture units of the card 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 per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Raster Operations Pipelines 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 lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.