GeForce GTX 660 vs Radeon HD 4850 X2 1GB

Intro

Compare those specifications to the Radeon HD 4850 X2 1GB, which comes with GPU clock speed of 625 MHz, and 1024 MB of GDDR3 memory set to run at 993 MHz through a 256-bit bus. It also is made up of 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 660		140 Watts
Radeon HD 4850 X2 1GB		250 Watts
	Difference: 110 Watts (79%)

Memory Bandwidth

The GeForce GTX 660 should in theory be a small bit faster than the Radeon HD 4850 X2 1GB overall. (explain)

GeForce GTX 660		144192 MB/sec
Radeon HD 4850 X2 1GB		127104 MB/sec
	Difference: 17088 (13%)

Texel Rate

The GeForce GTX 660 will be much (approximately 57%) better at anisotropic filtering than the Radeon HD 4850 X2 1GB. (explain)

GeForce GTX 660		78400 Mtexels/sec
Radeon HD 4850 X2 1GB		50000 Mtexels/sec
	Difference: 28400 (57%)

Pixel Rate

The GeForce GTX 660 should be a small bit (about 18%) faster with regards to FSAA than the Radeon HD 4850 X2 1GB, and able to handle higher resolutions more effectively. (explain)

GeForce GTX 660		23520 Mpixels/sec
Radeon HD 4850 X2 1GB		20000 Mpixels/sec
	Difference: 3520 (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.

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 MB per second) that can be transferred over the external memory interface in a second. It's worked out by multiplying the bus width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high 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 this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to its 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 card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.