----- "Martin" <[email protected]> wrote: > On Mon, 2010-10-25 at 23:31 +0300, Tarko Tikan wrote: > > hey, > > > > This is a fresh squeeze install on T5220 (same for the laptop I'm > comparing with). Whole machine seems strangely slow but one thing I > can point out for sure is bash. I've been debugging this issue for a > week now (even comparing strace -ttt time outputs with random intel > machine). Does this seem strange to anyone else?: > > > > randomx86laptop$ time (VAR=0; for i in `seq 0 99999`; do let > VAR=VAR+i; done) > > real 0m1.235s > > user 0m1.212s > > sys 0m0.036s > > > > niagara2$ time (VAR=0; for i in `seq 0 99999`; do let VAR=VAR+i; > done) > > real 0m11.193s > > user 0m10.777s > > sys 0m0.388s > > > > I first noticed this with bash_completion - every new bash instance > takes 2-3 seconds to start. > > > > Anyone have an idea whats going on? > > Can you give us a bit more info about the laptop? IIRC a T5220 runs > an > UltraSPARC T2 at about 1Ghz. These are designed for throughput, not > latency. The T2 is out of order but only 2 way dispatch (IIRC), > compared to a 3.4Ghz Intel chip with 4 way dispatch and full out of > order instruction completion. Thus in terms of single threaded > performance, I'm not exactly surprised an x86 laptop is 'faster'. A > factor of 10 seems a bit steep but 3-4 maybe 5 times I could believe. > However if you look at performance of code that is tightly branching, > memory latency/bandwidth sensitive or thread interaction critical, > you > should see scaling up to .. well ... it depends on the app but I've > seen > near linear speed up, up to 32 threads on T1s. > > What other benchmarks have you tried? Also have you tried with any > other OS (i.e. Open Solaris) on the same hardware; this should rule > out > anything Debian / Linux specific. Likewise have you tried other > machines? > > Cheers, > - Martin > >
Just for comparison purposes, the same command gives me the following on a much older Sunfire V100 (Ultrasparc IIe @ 500mhz) running Debian, and another of the same machine running Solaris 9: Debian 2.6.18-6-sparc64: real 0m10.534s user 0m10.213s sys 0m0.268s Solaris 9: real 0m10.985s user 0m9.620s sys 0m1.010s And then slightly faster on a Sun T6320 running Solaris_11_b130 (Ultrasparc T2 @ 1.2ghz) real 0m8.548s user 0m8.564s sys 0m0.045s -Brian -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected] Archive: http://lists.debian.org/25762851.19232.1288043933377.javamail.r...@zimbrapro
