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What is the difference between 32bit and 64 bit and which should I chose?
I bought a new lenovo ideapad Y560 with corei5 processor and windows7 64bit, but beside the windows I want to try the ubuntu too, but I need advice in this case, as I know this processors are supporting the 64bit architecture(win7 64bit still running on this), so what would be better, the ubuntu 32bit or 64bit, on this laptop.
try 64bit Ubuntu. it will give you good performance under i5 processor. Nowadays you will find 64bit versions for all important applications. Even flash has a 64bit alpha release which is quite stable. However, if you are an avid facebook user, you will have to use the 32 bit flash, as facebook fails to recognize 64bit flash. 32bit flash sometimes causes problems with certain websites on 64 bit ubuntu. Apart from that all applications run fine. My vote: 64bit Ubuntu on i5 processor :)
Through ia32 libs, the 64 bit version of ubuntu will be able to run 32 and 64 bit applications, so you would not miss out on anything. If you have 4gb of RAM or more, then you would also benefit from improved performance from the 64 bit version.
This article in Phoronix seems to confirm that 64-bit is faster than 32-bit in most cases. If your computer is capable of running a 64-bit OS, you probably should.