Can the "AMD Turion 64-X2" processor run 64 bit Ubuntu?

[Bill Stanley]

I need an opinion on this... Can the "AMD Turion 64-X2" processor run 64 
bit Ubuntu?

I want to install Ubuntu on a Dell Inspiron 1504  notebook computer and 
I am sure that the 32 bit version works but if the 64 bit version works 
also, I would install that instead.  The computers manual under 
specifications says the processor has

data width = 64 bits
processor address width = 40 bits.

Of course this says nothing about the address and data buses on the 
computer (only the processor).  My suspicion is that this is not a true 
64 bit processor.  The computer it is installed on also might not be 64 
bit.  Does anybody know what the true story is or is this just marketing 
double talk meant to confuse the consumer (meaning that it is actually a 
32 bit computer).

Also... I intend to upgrage the computer memory from the stock 512 MB to 
2 GB or more.   The manual says that 2 GB is the maximum but in some 
forums I have visited say that you can put up to 4 GB in the computer. 
Once again, does anybody out there know the answer to this one?

Bill Stanley