C1E (Enhanced Halt State) lowers the CPU voltage and clock speed when halt commands are issued by the operating system. This is a power saving option and would be one cause of the readings you are seeing with RealTemp.
However, I assume that under load your processor reports the fully overclocked speed. Unless you are experiencing problems with your overclock, having EIST (SpeedStep) and C1E enabled is actually not a bad thing.
Yeah, I wasn't doing much when I checked the temps. I'll check the speeds when playing Crysis later.