I now use Proxmox VE

use the tool esxcfg-advcfg

Get the current Active Policy

esxcfg-advcfg -get /Power/CpuPolicy

Low Power

esxcfg-advcfg -s low /Power/CpuPolicy

Balanced

esxcfg-advcfg -s dynamic /Power/CpuPolicy

High Performance

esxcfg-advcfg -s static /Power/CpuPolicy

or use esxcli

Get the current Active Policy

esxcli system settings advanced list -o "/Power/CpuPolicy"

Low Power

esxcli system settings advanced set -o "/Power/CpuPolicy" .string-value "low"

Balanced

esxcli system settings advanced set -o "/Power/CpuPolicy" -string-value "dynamic"

High Performance

esxcli system settings advanced set -o "/Power/CpuPolicy" -string-value "Static"

Remote from Linux

ssh root@ESXi-HOSTNAME-OR-IP esxcli system settings advanced set -o "/Power/CpuPolicy" -string-value "low"

from Windows

plink root@ESXi-HOSTNAME-OR-IP -l root -pw PASSWORD esxcli system settings advanced set -o "/Power/CpuPolicy" -string-value "low"

I now use Proxmox VE

Asus M4A89GTD PRO / VMware ESXi 5.1.0 Build 799733
AMD Phenom II X6 1075T
32 GB Memory (Corsair Vengeance 4 x 8 GB)
onBoard SATA
onBoard RTL8111E Network Controller
2 x Intel Gigabit CT Desktop Adapter
1 x Intel Pro/1000 PT Dual Port Server Adapter

Asus M4A78T-E BIOS 3406 / VMware ESXi 5.0.0 Build 469512
1 x Intel Pro/1000 PT Dual Port Server Adapter
2 x Intel Gigabit CT Desktop Adapter
onBoard SATA
Dawicontrol DC-7210 RAID (2 x 1 TB SATAII Raid 1)
16 GB Memory (Corsair Vegeance PC3-12800U)
AMD Athlon II X4 620 4x 2.60GHz

Asus M2NPV-VM / M2NPV-MX Beta BIOS 5005 / VMware ESXi 5.1.0 Build 799733
AMD Athlon 5050e Dual Core
8 GB Memory
Dawicontrol DC-7210 RAID (2 x 1 TB SATAII Raid 1)
onBoard SATA
onBoard nVidia NForce Network Controller
Intel Gigabit CT Desktop Adapter