GeForce GTS 250 512MB vs Radeon HD 3870 1GB

Intro

Compare those specifications to the Radeon HD 3870 1GB, which features core clock speeds of 775 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR4 memory. It features 320(64x5) SPUs as well as 16 Texture Address Units and 16 Rasterization Operator Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 1GB		106 Watts
GeForce GTS 250 512MB		145 Watts
	Difference: 39 Watts (37%)

Memory Bandwidth

As far as performance goes, the Radeon HD 3870 1GB should theoretically be a small bit better than the GeForce GTS 250 512MB in general. (explain)

Radeon HD 3870 1GB		72000 MB/sec
GeForce GTS 250 512MB		70400 MB/sec
	Difference: 1600 (2%)

Texel Rate

The GeForce GTS 250 512MB is much (approximately 281%) more effective at texture filtering than the Radeon HD 3870 1GB. (explain)

GeForce GTS 250 512MB		47232 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 34832 (281%)

Pixel Rate

The Radeon HD 3870 1GB is a little bit (more or less 5%) better at full screen anti-aliasing than the GeForce GTS 250 512MB, and also able to handle higher screen resolutions more effectively. (explain)

Radeon HD 3870 1GB		12400 Mpixels/sec
GeForce GTS 250 512MB		11808 Mpixels/sec
	Difference: 592 (5%)

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 data (in units of MB per second) that can be transported over the external memory interface in one second. The number is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR type RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total number of texture units of the card by the core clock 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 processed in a second.

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