On Wed, Jul 25, 2012 at 10:02:58AM +0200, Sascha Wildner wrote: > As Brian Mastenbrook pointed out in a comment on the digest, the > Atom should support P4TCC: > > http://www.shiningsilence.com/dbsdlog/2012/07/24/10128.html > > Check your CPU features in dmesg. It should show the TM feature, as > it does on my Atom 330 (second to last): > > Features=0xbfe9fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE> > > Compiling the kernel with CPU_ENABLE_TCC gives new dmesg and sysctls: > > almsta# grep TCC /var/run/dmesg.boot > Pentium 4 TCC support enabled, current performance 13% > almsta# sysctl hw.p4tcc > hw.p4tcc.cpuperf: 13 > hw.p4tcc.cpuperf_performance: 100 > hw.p4tcc.cpuperf_economy: 13 > > However, a quick test with factor(6) showed no difference between 13 > and 100: > > almsta# sysctl hw.p4tcc.cpuperf=100 > hw.p4tcc.cpuperf: 13 -> 100 > almsta# time factor 234241111111 > 234241111111: 7 7 4780430839 > 4.726u 0.000s 0:04.77 98.9% 16+66k 0+0io 0pf+0w > > almsta# sysctl hw.p4tcc.cpuperf=13 > hw.p4tcc.cpuperf: 100 -> 13 > almsta# time factor 234241111111 > 234241111111: 7 7 4780430839 > 4.726u 0.007s 0:04.77 98.9% 16+66k 0+0io 0pf+0w > > Anyway, if your system is i386, try out adding "options > CPU_ENABLE_TCC" to the config and see what it gives. > > I'll see later today about providing it for x86_64 too. > > Sascha
Thanks a lot for all the hints. I will try this options these days and get back with the results. Sven
