cpufreq-bench: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/sbin/cpufreq-bench - from package: cpupowerutils

You may install the required package with command yum install {package}
Error in other languages:
cpufreq-bench: bevel nie gevind nie
cpufreq-bench: comandă negăsită
cpufreq-bench: comando não encontrado
cpufreq-bench: commande introuvable
cpufreq-bench: command not found
cpufreq-bench: käsku ei ole
cpufreq-bench: không tìm thấy lệnh
cpufreq-bench: komanda nerasta
cpufreq-bench: Kommando nicht gefunden.
cpufreq-bench: kommandot finns inte
cpufreq-bench: komut yok
cpufreq-bench: nie znaleziono polecenia
cpufreq-bench: níor aimsíodh an t-ordú
cpufreq-bench: no se encontró la orden
cpufreq-bench: no s'ha trobat l'ordre
cpufreq-bench: opdracht niet gevonden
cpufreq-bench: parancs nem található
cpufreq-bench: perintah tidak ditemukan
cpufreq-bench: príkaz nenájdený
cpufreq-bench: příkaz nenalezen
cpufreq-bench: команда не найдена
cpufreq-bench: командата не е открита
cpufreq-bench: 命令找不到
cpufreq-bench: コマンドが見つかりません