Regression of that size. No problem. The linear regression procedures (REG, GLM, etc), use memory based on the number of variables and generally make one pass through the data for each execution of the procedure.
Other regression type procedures (LOGISTIC, PHREG) use search algorithms that do run through the data multiple times and potentially take days to run.
The reference manual has some information on the execution algorithms in the "details" section of each chapter.