Thanks all for your input. The problem is solved in a way.
Before mucking with hardware i tried few software things. With 2.0.36 compiled as 686 and as 586 i had only 350Bogomips with a 350MHz K6-2 BUT (!) with 2.2.0pre7 compiled with CONFIG_M586TSC=y i have my full 700 bogomips ! with it /proc/cpuinfo shows everything right (CPU clock,etc...) That's strange isn't it ? Probably a strange compilation quirk somewhere.... I'll stick with 2.0.36 for now (as 350Bogomips should be enough to serve only few web pages), but i will wait anxiously to 2.2.0 final Patrick