My machine is a dell inspiron mini 1012,it has a 1 gb memory. I have installed ubuntu 11.10 on it, but it works very slow. now I want to install 12.04 and I want to know which configuration is better for my computer according with its memory, 32 bits or64 bits. I only want my computer to work faster. I dont know if this information is enough , if you want more info tell me.
For a 1GB system, the best to do is install the 32 Bit version, unless you want to upgrade your system memory in the near future. The 32 Bit works better with most of low memory systems. Plus, you'll get better memory performance from a 32-bit version.
I would recommend 32bit.
For me it's enough, Dell Inspiron Mini 1012 has Intel Atom N450, which is a 1-core 64-bit Intel processor, so little bit faster should be a 64-bit OS. But the difference from my point of view isn't very big.
From: https://help.ubuntu.com/community/32bit_and_64bit
Nevertheless, as Mitch answered and on this question on Stackoverflow, you may encounter some shortage of memory during some operations, so I think, that, yeah, faster would be a 64-bit Ubuntu, but when you encounter greedy applications, it will become much slower then. So for fast listening music, watching movies etc. I still recommend 64-bit, but to process videos and using gimp, etc. memory is much bigger issue, so than 32-bit.