> > One way to check how well softfp performs would be to run povray in > > Ubuntu versus in Debian; this will mix noise in the results, but I > > don't expect the minor sourceful differences to make the biggest > > impact, but rather the toolchain opts would. (You're speaking of a > > 3-folds increase.) > > I don't have a debian armel installation here, so I can't test how it > performs there, however running the same version on a g...@1ghz running > squeeze -no altivec- I got total runtime 20 seconds, which is imho > indicative of the potential performance of the imx...@800mhz, as the ARM > vfp is much less powerful than the G4's. 20 vs 50, sounds almost expected, > 20s vs ~3min sounds like a joke.
Based on what evidence? The G4 has an single cycle pipelined out-of-order FPU. The A8 has a non-pipelined FPU that takes between 5 and 20 (normal single precision is 10) cycles to give a result. A 9x slowdown sounds right on the ball. Altivec v.s. NEON is a somewhat different question, there's only a 2x difference in peak performance there. Paul -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected] Archive: http://lists.debian.org/[email protected]
