GeForce GTX 660 vs Radeon HD 4850 512MB

Intro

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

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4850 512MB		110 Watts
GeForce GTX 660		140 Watts
	Difference: 30 Watts (27%)

Memory Bandwidth

As far as performance goes, the GeForce GTX 660 should in theory be much better than the Radeon HD 4850 512MB overall. (explain)

GeForce GTX 660		144192 MB/sec
Radeon HD 4850 512MB		63552 MB/sec
	Difference: 80640 (127%)

Texel Rate

The GeForce GTX 660 should be a lot (more or less 214%) faster with regards to anisotropic filtering than the Radeon HD 4850 512MB. (explain)

GeForce GTX 660		78400 Mtexels/sec
Radeon HD 4850 512MB		25000 Mtexels/sec
	Difference: 53400 (214%)

Pixel Rate

The GeForce GTX 660 is quite a bit (more or less 135%) more effective at anti-aliasing than the Radeon HD 4850 512MB, and also able to handle higher resolutions without losing too much performance. (explain)

GeForce GTX 660		23520 Mpixels/sec
Radeon HD 4850 512MB		10000 Mpixels/sec
	Difference: 13520 (135%)

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 information (in units of MB per second) that can be transported over the external memory interface in a second. It is worked out by multiplying the interface width by its memory clock speed. If the card has DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better 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 texture map elements (texels) that can be processed in one second. This 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 handling 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 could possibly record to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also 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, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.