Ralf, Thanks for the input. > > a 3 % reduction in the Memory Index benchmark > > a 2 % increase in the Integer Index benchmark > > a 23 % reduction in the Floating Point Index > benchmark > > Small fluctuations in the range of 2 or 3 percent > are usually explained > by a changing usage pattern of the caches. > Therefore rerunning a the > benchmarks is a good idea. Especially > microbenchmarks a la lmbench on > caches of low associativity like the direct mapped > R4k caches are extremly > easily affected by cache usage patterns. I messed up the figures for the redhat 7.1 case They should have been : Memory Index 6.7 % decrease Integer Index 2 % decrease Floating Point 27 % decrease And it was the progressive reduction in performance of the Memory Index that was raising a red flag to me. Especially the big hit in floating point performance. > Did you get any kernel messages during the Floating > Point Index benchmark > on the older kernel? No, everything ran fine. > > newer kernel and with a newer distribution ? newer > > compiler ? > > Gcc 3.0 has been reported to produce slightly slower > code than it's > predecessor by many people on various architecture. > I'm sad to find that > MIPS is also one of them. OK. That's one to remember. > As for the kernel - I don't really know; your > analysis isn't fine grained > enough. I didn't do any performance tweaking with the kernel itself as I wouldn't really know how to go about it. I was more trying to use a base kernel and then see how I could improve the benchmark performance by using compile options on the benchmark program only. Admittedly improving kernel performance is a far more efficient way of improving the benchmark scores. > Successful tuning requires a detailed analysis > first. I read an article recently in Linux Journal on tweaking an Alpha kernel. I suppose the same general principles can be applied to MIPS. Alternatively, do you ( or anyone else ) know of a howto or even a general article on how to do this ? I downloaded the benchmark from : http://www.tux.org/~mayer/linux/bmark.html Wayne __________________________________________________ Do You Yahoo!? Make international calls for as low as $.04/minute with Yahoo! Messenger http://phonecard.yahoo.com/
