I bought a new laptop, a Intel i3 with 4Gb ram. I wish to load Ubuntu 12.04LTS 64x to make use of all 4Gb ram. Can I load Ubuntu 64x on an i3 even if it is not an AMD and if so will it make full use of 4 Gb ram i hope?
There is no problem with i3 ( Its a 64 bit processor and support 32bit mode as well). You can load any version of ubuntu to that.
However in this case you can install either 64bit version or 32bit version, there will be no change as your ram size is 4GB.
Maximum memory supported by a 32bit OS (without PAE kernel) is
For more than 4GB ram , you should consider 64 bit.
Refer here for more details.