On Mon, 2003-12-15 at 22:19, lrtaylor@xxxxxxxxxx wrote: > Which version of GCC are you using (that is, 3.3.0, 3.3.1 or 3.3.2)? From what I understand, there was a bug report for that and it was supposed to have been fixed in 3.3.2, or is slated to be fixed soon. It had to do with the I/O implementation calling a slow system function (something like snprintf or something). Perhaps someone knows better than I, but I know it's definitely not fixed in 3.3.1 or earlier. > > Cheers, > Lyle I tested today on a different machine (running debian sarge) the 2.95.4 against 3.3.2 performance. Unfortunately the results were the same, or let's say at least quite similar. Without I/O the g++-3.3.2 compiled program ran 10% faster With lot's of writing to cout, 3.3.2 ran 50% slower That's a better result than the 80% slower I'm gettin on my other machine but that could be also because its different hardware (PentiumIII against Athlon-XP). Anyways, I find 50% drop in performance hard to swallow. Does anybody know if this issue is discussed for gcc development? Regards, Torsten > -----Original Message----- > From: gcc-help-owner@xxxxxxxxxxx [mailto:gcc-help-owner@xxxxxxxxxxx]On > Behalf Of Torsten Reuss > Sent: Monday, December 15, 2003 2:08 PM > To: gcc-help@xxxxxxxxxxx > Subject: g++ 3.3 I/O Performance > > > Hi, > > I'm wondering if anybody can help me on why g++-3.3 is about 80% slower > than g++-2.95.4 for an I/O intensive program I'm working on. > > Now, before I go into the details, that's 80% slower with a call to > ios::sync_with_stdio(false) inserted already. Without that it was 5 > times slower. >
