They should be near-identical in time (and bear in mind that SQL's timers aren't accurate down to the ms level, that's stats time and perfmon). While the second does do more work and will use more CPU, it's likely to be a very small amount compared to the time to retrieve all the data (no filters on those queries)
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability