It adds a bunch of indexes, yes. I don't think anyone really runs TPC-H unindexed unless they are using a database that plain doesn't support it; it wouldn't really give much meaningful information.

Edit: I seemingly don't have these benchmarks anymore, and I'm not going to re-run them now, but I found a very (_very_) roughly similar SF10 run clocking in around seven minutes total. So that's the order of magnitude I would be expecting, given ten times as much data.