There is more than one model within that Samsung Ultrabook Series 5 series designation, so you should look up specs for the EXACT model designation.
I did look up results for one that I found, and it looks like that has 4 GB of integrated memory, with a single slot for adding additional memory - of the DDR33 1600 type. IF this is accurate, then if you went with this model I would suggest picking up 1 $B strip of DDR3 1600 memory to give you a total of 8 GB, which will help performance with Sonar.
It also appears that this model's motherboard does NOT have its own dedicated graphics chip, rather, it seems to rely on the graphics capability of the CPU itself. This means that graphics memory will be allocated from your available main memory, which reinforces my suggestion of picking up that additional 4 GB strip for a total of 8 GB.
The i5 CPU should be plenty fast enough, and even though some memory would be used by the graphics, that should leave you enough memory to handle Sonar with reasonable performance, particularly for travel purposes.
The above is the opinion I have for reviewing the specs from the following link:
http://www.notebookcheck.net/Review-Samsung-Series-5-530U3C-A01DE-Ultrabook.77219.0.html As noted in the above review, there is at least one other older model, still called a series 5, so be sure you know which one of these you are purchasing.
Bob Bone