Intel Core 2 Duo E8800 (ES)
Intel Core 2 Duo E6200 (ES)
Intel Core 2 Duo E7700
Intel Pentium II 266 (0,35µ)
Intel Core 2 Duo E7800
Means High Frequency Mode.
It is a functionnal mode where a cpu featuring Intel Speedstep Technology or Intel Enhanced Speedstep Technology (EIST) work at its nominal frequency.
Also called "Maximum Performance Mode" with first generation Intel Speedstep Technology.