| EST(4) | Kernel Interfaces Manual | EST(4) | 
NAME
 est — Enhanced SpeedStep
SYNOPSIS
 est0 at cpu0
DESCRIPTION
 The 
est driver provides support for Enhanced SpeedStep introduced in Intel's first and second generation of Pentium M processors. The following 
sysctl(8) variables are available with 
est:
- 
machdep.est.frequency.target
- 
The target frequency of the CPUs.
- 
machdep.est.frequency.current
- 
The current frequency.
- 
machdep.est.frequency.available
- 
The frequencies recognized by est.
Note, however, that these variables are not guaranteed to exist in the future versions of NetBSD.
 
SEE ALSO
 acpicpu(4), 
odcm(4), 
powernow(4)
Intel Corporation, Intel Pentium M Processor., Datasheet, http://download.intel.com/support/processors/mobile/pm/sb/25261203.pdf, March, 2004.
Intel Corporation, Enhanced Intel SpeedStep Technology for the Intel Pentium M Processor., White Paper, http://download.intel.com/design/network/papers/30117401.pdf, March, 2004.
 
CAVEATS
 The 
est driver is considered a legacy interface to be used only with old systems. It is known to be problematic with new CPUs. Furthermore, in the unlikely case where both 
est and 
ichlpcib(4) or 
piixpcib(4) provide support for SpeedStep, the PCI-based interfaces should not be accessed due possible race conditions.