If you are running HLDS on a Windows Server or you manage your server via FTP, you may never see this error throughout your life.
Unable to determine CPU Frequency
Since I am running HLDS on CentOS Virtual Machine (using Virtual Box), I occasionally see new errors like this one. The reason behind using VM is that CentOS is much stable as compared to Windows Server 2003/2008/2012 which is notorious for crashes and messy permission issues. The complete error message that I received on console was this:
Auto detecting CPU
Using Pentium II Optimised binary.
Auto-restarting the server on crash
Unable to open tty(/dev/tty) for output

Console initialized.
Using breakpad crash handler
Setting breakpad minidump AppID = 10
Forcing breakpad minidump interfaces to load
Unable to determine CPU Frequency. Try defining CPU_MHZ.

Everything else was running fine on that VM except HLDS. I ran cat /proc/cpuinfo on Linux console and got this result:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 30
model name : Intel(R) Xeon(R) CPU X3440 @ 2.53GHz
stepping : 5
microcode : 1558
cpu MHz : 0.000
cache size : 6144 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 5
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 rdtscp constant_tsc up pni monitor ssse3
bogomips : 5066.83
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:

As you can see, the “cpu MHz” is shown as “0.000” which is not normal.
Linux cpuinfo 0.000 MHz
This error was initially seen when I installed CentOS on VBox for the first time and ran HLDS binary. After spending many hours trying to figure out the problem, I came across this simple fix:
Open the VM’s settings and change Chipset to ICH9 in System tab.
VirtualBox System ICH9 Settings
In Storage tab, change Type to ICH6 and press Ok.
VirtualBox Storage Type ICH6
Now start the VM and type cat /proc/cpuinfo | grep "cpu MHz" in Linux console. You should see something like this:
CentOS cpuinfo Normal
Your HLDS should be running fine now!