GeForce GTS 250 1GB vs Radeon HD 4850 X2 512MB

Intro

Compare that to the Radeon HD 4850 X2 512MB, which features GPU clock speed of 625 MHz, and 512 MB of GDDR3 memory set to run at 993 MHz through a 256-bit bus. It also is comprised of 800(160x5) Stream Processors, 40 TAUs, and 16 Raster Operation Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTS 250 1GB		145 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 105 Watts (72%)

Memory Bandwidth

Performance-wise, the Radeon HD 4850 X2 512MB should theoretically be quite a bit better than the GeForce GTS 250 1GB in general. (explain)

Radeon HD 4850 X2 512MB		127104 MB/sec
GeForce GTS 250 1GB		70400 MB/sec
	Difference: 56704 (81%)

Texel Rate

The Radeon HD 4850 X2 512MB is just a bit (about 6%) faster with regards to texture filtering than the GeForce GTS 250 1GB. (explain)

Radeon HD 4850 X2 512MB		50000 Mtexels/sec
GeForce GTS 250 1GB		47232 Mtexels/sec
	Difference: 2768 (6%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon HD 4850 X2 512MB is the winner, by far. (explain)

Radeon HD 4850 X2 512MB		20000 Mpixels/sec
GeForce GTS 250 1GB		11808 Mpixels/sec
	Difference: 8192 (69%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the maximum amount of data (in units of megabytes per second) that can be transferred across the external memory interface in one second. The number is calculated by multiplying the card's interface width by its memory speed. In the case of DDR RAM, it should be multiplied by 2 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, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This is calculated by multiplying the total amount of texture units by the core 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 a second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.