GeForce 8800 GT 512MB vs Radeon HD 4850 2GB

Intro

Compare that to the Radeon HD 4850 2GB, which makes use of a 55 nm design. ATi has clocked the core frequency at 625 MHz. The GDDR4 memory runs at a speed of 993 MHz on this specific model. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8800 GT 512MB		105 Watts
Radeon HD 4850 2GB		110 Watts
	Difference: 5 Watts (5%)

Memory Bandwidth

In theory, the Radeon HD 4850 2GB will be 10% quicker than the GeForce 8800 GT 512MB in general, due to its greater data rate. (explain)

Radeon HD 4850 2GB		63552 MB/sec
GeForce 8800 GT 512MB		57600 MB/sec
	Difference: 5952 (10%)

Texel Rate

The GeForce 8800 GT 512MB should be a lot (approximately 34%) better at anisotropic filtering than the Radeon HD 4850 2GB. (explain)

GeForce 8800 GT 512MB		33600 Mtexels/sec
Radeon HD 4850 2GB		25000 Mtexels/sec
	Difference: 8600 (34%)

Pixel Rate

The Radeon HD 4850 2GB is a bit (more or less 4%) better at full screen anti-aliasing than the GeForce 8800 GT 512MB, and also capable of handling higher screen resolutions while still performing well. (explain)

Radeon HD 4850 2GB		10000 Mpixels/sec
GeForce 8800 GT 512MB		9600 Mpixels/sec
	Difference: 400 (4%)

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 largest amount of data (counted in megabytes per second) that can be moved across the external memory interface within a second. It's calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better 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 can be processed per second. This figure is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.