Sony Vaio VGN-FE660G went with Core Duo T2300 1.6GHz processor built in, and Sony Vaio VGN-FE31Z with Core 2 Duo T5600 1.83GHz.
Sony Vaio VGN-FE660G and Sony Vaio VGN-FE31Z have same 15.4" screen size.
The same on both notebooks is maximum screen resolution - 1280x800.
Although memory could easily be expanded, 2GB on Vaio VGN-FE31Z versus 1GB on Vaio VGN-FE660G might be significant difference.
There are more free RAM slots available on Vaio VGN-FE660G - 1.
Vaio VGN-FE660G weigths less with its 2.8kg than the another one.
Graphic card in use in Sony Vaio VGN-FE660G is Intel 950 and in Sony Vaio VGN-FE31Z is Nvidia Go 7600.
Sony Vaio VGN-FE31Z laptop is more suitable with its 200GB hard drive for storing bunch of media information like music and movies.
We do not have preference on their hard disk speed - 5400 rpm have both.
There are no bluetooth on Sony Vaio VGN-FE660G and that might be disadvantage.
If you have infrared enabled devices if you buy Sony Vaio VGN-FE660G you won't be enabled to communicate with them.
Firewire is embedded in both allows them to communicate with other IEEE 1394 devices like some camcorders.
If you sometimes travel to destination without broadband internet connection, you don't have to worry since both laptops have internal modems.
Both laptops have cardreaders.
None has DVI output so you cannot connect them to some new LCD monitors.
The number of USB ports is 3 on both.
Web camera is built in Sony Vaio VGN-FE31Z (the another hasn't it) and it is useful for video conferencing.
Operating system is XP Media Center.
There are some special software suits and software packs with both : Adobe Acrobat Elements 7.0, Works, Photshop Elements, DV Gate Plus, WinDVD, Roxio Digital Media SE7, Norton Internet Security 2006, Skype 2,0 with Sony Vaio VGN-FE31Z and Works 8.5 with Sony Vaio VGN-FE660G.
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