We already informed that processors Conroe recently have passed on mysterious new stepening. which we have considered as C1 stepening . Processors on its basis were overclocked up to 4.0 GHz using only a powerful air coolers.
Today we have found out on pages of XtremeSystems.org forum the indicative of such result by one French overclocker. This cpu was Core 2 Duo E6600 (2.4 GHz) stepening C1, and CPU-Z utility version 1.34.2 has correctly reconnaized the step of this processor

That more interesting fact is after the increase of vcore voltage up to 1.56v and using Noctua NH-U12 cooler it was possible to overclock the processor up to 4.1 GHz frequency,
The cpu was even capable to run super pi benchmark
however today's experiment has revealed a weak part in the overclocking of Conroe C1 processor . once again risk to become motherboard limit. : processor Core 2 Duo E6600 with a 9x multiplier , concerning that the most expensive models Conroe is used, and frequency of the system bus has already reached 456 MHz. For many parent motherboard it can become a stop limit. chances of similar overclock using younger Conroe models with lower multipliers are for sure a lot lower.
hoping, that motherboard on the basis of P965 chipset and chipsets ATI/nVidia witch support Conroe can provide high fsb capability to successful overclock younger models . The limit in 500-600 MHz on the system bus should become a desirable minimum for good conroe overclocker motherboard .