Question: What is the max file size that SAS software can successfully read.
(without considering hardware limit)

Thanks in advance.

Answer: 
To quote a recently running TV commercial, the answer is "infinity plus 1".

SAS does not have any limitation on the size of a file during read operations, although it's possible you might run into a limit on the number of observations written to a new SAS data set. On a 64-bit system, that would be 2\*\*63-1, about 9.2 quintillion observations. You are more likely to run out of disk space.
Depends on HOW you read the file. If loading a hash table for instance, you are limited by memory.. If you are reading via a set or infile statement, with no or limited size output dataset, you are limited by the 'uptime' of your process - eg if / when you are forcibly logged off, or become disconnected from whatever you are reading.

Also, some datasets (eg with a large number of columns) may be impossible to read, as cannot load all the variables into the PDV due to memory limits. Again, this is an OS limitation and not SAS.