GeForce GTS 250 512MB vs Radeon HD 4850 512MB

Intro

Compare those specifications to the Radeon HD 4850 512MB, which comes with a core clock speed of 625 MHz and a GDDR3 memory frequency of 993 MHz. It also features a 256-bit memory bus, and makes use of a 55 nm design. It is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4850 512MB		110 Watts
GeForce GTS 250 512MB		145 Watts
	Difference: 35 Watts (32%)

Memory Bandwidth

Theoretically speaking, the GeForce GTS 250 512MB should be 11% faster than the Radeon HD 4850 512MB overall, due to its higher data rate. (explain)

GeForce GTS 250 512MB		70400 MB/sec
Radeon HD 4850 512MB		63552 MB/sec
	Difference: 6848 (11%)

Texel Rate

The GeForce GTS 250 512MB should be quite a bit (approximately 89%) faster with regards to texture filtering than the Radeon HD 4850 512MB. (explain)

GeForce GTS 250 512MB		47232 Mtexels/sec
Radeon HD 4850 512MB		25000 Mtexels/sec
	Difference: 22232 (89%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the GeForce GTS 250 512MB is a better choice, not by a very large margin though. (explain)

GeForce GTS 250 512MB		11808 Mpixels/sec
Radeon HD 4850 512MB		10000 Mpixels/sec
	Difference: 1808 (18%)

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 maximum amount of information (measured in MB per second) that can be transported over the external memory interface in a second. The number is calculated by multiplying the card's bus width by the speed of its memory. In the case of DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. 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 are applied per second. This figure is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The better the texel rate, 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 graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.