Something strange is occurring with time-related utilities on my Alpha 21164. In doing my timings of Mlucas 2.6c, my trial indicated (among other things) a per-iteration time of 0.48 sec/iteration at FFT length 384K. After finishing my 100-iteration timing tests, I started a test of a Mersenne number in the 7M range. The 2000-iteration timings in the status file match the .48 second estimate. But, 24 hours (both according to the Unix ps command and on my wall clock) later, the code had completed 240000 iterations, corresponding to just 0.36 sec/iteration. While this is welcome, I'm baffled - whatever the problem is, it's affecting both the time utility and the time the program gets from the system CPU counter, but it's not affecting the actual displayed system time or things like the ps utility. The fact that the actual elapsed time is exactly 3/4 the time reported by the code (and the time utility) seems to indicate that there's some kind of 400/533 MHz clock rate mismatch going on. System details: It's a 400MHz 21164A (i.e. ev56) running Unix V4.0D. Has anyone else run into such a problem? Can someone else running the code on a 21164 see if there's a mismatch between the timings reported in the status file and the actual per-hour or per-day iterations performed? Puzzled (but not unhappy), -Ernst _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
